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৪৯তম বিসিএস ⎯ কম্পিউটার সায়েন্স (CSE) [৯৭১]

পরীক্ষা৪৯তম বিসিএস ⎯ কম্পিউটার সায়েন্স (CSE) [৯৭১]তারিখতারিখ অনির্ধারিতসময়01 hr 30 mins
মোট প্রশ্ন১০৯
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উত্তরিতবর্তমানপুনরায় দেখুনঅসম্পূর্ণ

৪৯তম বিসিএস ⎯ কম্পিউটার সায়েন্স (CSE) [৯৭১]

৪৯তম বিসিএস ⎯ কম্পিউটার সায়েন্স (CSE) [৯৭১] · তারিখ অনির্ধারিত · ১০৯ প্রশ্ন

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'Buddhist Mystic Songs' গ্রন্থে চর্যাপদের কত জন কবির নাম উল্লেখ আছে?
  1. ২১ জন
  2. ২২ জন
  3. ২৩ জন
  4. ২৪ জন
ব্যাখ্যা

চর্যাপদের কবিগণ:
- সুকুমার সেনের 'বাঙ্গালা সাহিত্যের ইতিহাস' (প্রথম খণ্ড) গ্রন্থে চর্যাপদের ২৪ জন পদকর্তার নাম পাওয়া যায়। ড. মুহম্মদ শহীদুল্লাহ সম্পাদিত 'Buddhist Mystic Songs' গ্রন্থে চর্যাপদের ২৩ জন কবির নাম উল্লেখ আছে

এরা হলেন:
- কাহ্নপা; কুক্কুরীপা; ধর্মপা; ঢেগুণপা; বিরুপা; বীণাপা; ভাদেপা; ভুসুকুপা, মহীধরপা, লুইপা; শবরপা; শান্তিপা; সরহপা; ডোম্বীপা; কম্বলাম্বরপা; গুণ্ডুরীপা; চাটিল্লপা; আর্যদেবপা; দারিকপা; তাড়কপা; কঙ্কণপা; জয়নন্দীপা; তন্ত্রীপা।

উৎস: বাংলা ভাষা ও সাহিত্য জিজ্ঞাসা, বাংলা সাহিত্যের ইতিহাস, মাহবুবুল আলম।

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Love for Love is written by -
  1. William Congreve
  2. Samuel Richardson
  3. George Bernard Shaw
  4. Christopher Marlowe
ব্যাখ্যা

• Love for Love:
- It is a play written by William Congreve.
- এটি মুলত একটি comedy play.
- William Congreve ছিলেন Restoration Period এর একজন বিখ্যাত সাহিত্যিক।
- He wrote some of the most popular plays in English literature.

• William Congreve:
- তিনি একজন English dramatist.
- তিনি comedy of manners এর জন্য বিখ্যাত।
- তিনি Restoration period এর একজন বিখ্যাত সাহিত্যিক।
- He wrote some of the most popular plays in English literature.

• Notable works:
- Love for Love,
- The Double-Dealer,
- The Mourning Bride,
- The Way of the World.

Source: Britannica, Live MCQ Lecture.

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কৌলীন্য প্রথার উদ্ভব কোন শাসনামলে হয়েছিল বলে মনে করা হয়?
  1. সেন
  2. পাল
  3. গুপ্ত
  4. মুঘল
ব্যাখ্যা

- কৌলীন্য প্রথার উদ্ভব পাল শাসনামলে হয়েছিল বলে মনে করা হয়।

কৌলীন্য প্রথা:

- রাঢ় ও বরেন্দ্র এর ব্রাহ্মণদের মধ্যে কৌলীন্য প্রথা অধিক মাত্রায় প্রভাব বিস্তার করেছিল।
- তারা সম্ভবত কান্যকুব্জের পাঁচ ব্রাহ্মণ-রক্ষিতীশ, মেধতিথী, বিতরগ, সুধনিধি এবং সম্ভরি-এর উত্তরসূরি।
- গৌড়ের রাজা শশাঙ্ক এবং বর্মণ রাজা হরিবর্মণ উভয়েই যথাক্রমে শকদ্বীপী ও বৈদিক ব্রাহ্মণ নিয়ে এসেছিলেন বলে জানা যায়।
- বলা হয়ে থাকে, এ ব্রাহ্মণদের সাথে সম্পর্ক সৃষ্টির ফলস্বরূপ বাংলায় সামাজিক প্রথা হিসেবে কৌলিন্য প্রথার সূত্রপাত হয়েছে।
- সেন রাজা বল্লালসেনকেও কৌলিন্য প্রথার স্রষ্টা হিসেবে কৃতিত্ব দেওয়া হয়, যদিও এ দাবির সমর্থনে সেন যুগের কোনো সাহিত্যিক ও উৎকীর্ণলিপি প্রমাণ পাওয়া যায়নি।
- তৃতীয় বিগ্রহপালের বনগাঁ তাম্রশাসনে ইঙ্গিত করা হয়েছে, তাঁর কর্মকর্তা ঘন্তিস-এর প্রো-পিতামহের মাধ্যমে তাঁর পূর্বপুরুষের সাথে কোলঞ্চ (কান্যকুব্জ) ব্রাহ্মণ কচ্ছ-এর যোগসূত্র ছিল।
- ফলে কৌলীন্য প্রথার উদ্ভব পাল শাসনামলে হয়েছিল বলে মনে করা হয়।

উল্লেখ্য,
- কুলীন অর্থ হলো উত্তম পরিবার বা সম্ভ্রান্ত বংশজাত।
- বাচস্পতি মিশ্র-এর মতে, এটি চিহ্নিত হয় আচার (শুদ্ধতা), বিদ্যা (জ্ঞান), বিনয় (শৃঙ্খলাবোধ), প্রতিষ্ঠা (শুদ্ধতার খ্যাতি), তীর্থ-দর্শন (তীর্থযাত্রা), নিষ্ঠা (কর্তব্যনিষ্ঠা), তপস্যা (কঠোর ধ্যান), আবৃত্তি (সমবর্ণে বিবাহ) এবং দান (উদারহস্ত) দিয়ে।

উৎস: বাংলাপিডিয়া।[লিঙ্ক]

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কোন শাসকের পরাজিত করার পর সমগ্র বাংলা অঞ্চলে মুঘল সুবাদারি প্রতিষ্ঠিত হয়?
  1. পাল বংশ
  2. বারোভূঁইয়া
  3. সেন বংশ
  4. কাররানি বংশ
ব্যাখ্যা

• বাংলায় মুঘল শাসন (১৫৭৬-১৭৫৭ সাল):
- সুবাদারি ও নবাবি-এ দুই পর্বে বাংলায় মুঘল শাসন অতিবাহিত হয়।
- বারোভূঁইয়াদের পরাজিত করার পর সমগ্র বাংলা অঞ্চলে মুঘল সুবাদারি প্রতিষ্ঠিত হয়।
- মুঘল প্রদেশগুলো 'সুবা' নামে পরিচিত ছিল।
- বাংলা ছিল মুঘলদের অন্যতম সুবা। সতেরো শতকের প্রথম দিক থেকে আঠারো শতকের শুরু পর্যন্ত ছিল সুবাদারি শাসনের স্বর্ণযুগ।
- সম্রাট আওরঙ্গজেবের পর দিল্লির দুর্বল উত্তরাধিকারীদের সময়ে মুঘল শাসন শক্তিহীন হয়ে পড়ে।
- এ সুযোগে বাংলার সুবাদারগণ প্রায় স্বাধীনভাবে বাংলা শাসন করতে থাকেন।
- মুঘল আমলের এই যুগ 'নবাবি আমল' নামে পরিচিত।

উৎস: বাংলাদেশের ইতিহাস ও বিশ্বসভ্যতা, নবম-দশম শ্রেণি।

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জুলাই ঘোষণাপত্র কত নং দফায় জুলাই শহীদদের 'জাতীয় বীর' ঘোষণা করা হয়েছে ?
  1. ২৮ নং
  2. ২৪ নং
  3. ২৬ নং
  4. ২২ নং
ব্যাখ্যা

জুলাই ঘোষণাপত্র':
- ৫ আগস্ট অন্তর্বর্তী সরকারের প্রধান উপদেষ্টা অধ্যাপক ড. মুহাম্মদ ইউনূস পাঠ করেন ২৮ দফা সংবলিত 'জুলাই ঘোষণাপত্র'।
- ২৪ নং দফায় জুলাই গণঅভ্যুত্থানের সকল শহীদদের জাতীয় বীর হিসেবে ঘোষণা করে।
- শহীদদের পরিবার, আহত যোদ্ধা এবং আন্দোলনকারী ছাত্রজনতাকে প্রয়োজনীয় সকল আইনি সুরক্ষা দেওয়ার অভিপ্রায় ব্যক্ত করেছে।

উৎস: দৈনিক ইত্তেফাক।[লিঙ্ক]

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২০২৫ সালে নজরুল পুরস্কার পেয়েছেন-
  1. ইরশাদ আহমেদ শাহীন ও রুমী আজনবী
  2. নাসিম আহমেদ ও আবদুল হাই শিকদার
  3. আনোয়ারুল হক ও শবনম মুশতারী
  4. আনোয়ারুল হক ও মোহাম্মদ আজম
ব্যাখ্যা

নজরুল পুরস্কার-২০২৫:
- ২০২৫সালে জাতীয় কবি কাজী নজরুল ইসলামের ১২৬তম জন্মবার্ষিকী ছিল।
- এ বছর পুরস্কার পেয়েছেন নজরুল গবেষক অধ্যাপক আনোয়ারুল হক এবং নজরুল সংগীতশিল্পী শবনম মুশতারী।
- বাংলা একাডেমির আবদুল করিম সাহিত্যবিশারদ মিলনায়তনে অনুষ্ঠিত এক সেমিনারে এ পুরস্কার প্রদান করা হয়।

উল্লেখ্য,
- বাংলা একাডেমির সভাপতি অধ্যাপক আবুল কাসেম ফজলুল হক।
- মহাপরিচালক অধ্যাপক মোহাম্মদ আজম।
- ২০২২ সালে বাংলা একাডেমি নজরুল পুরস্কার চালু করে।
- পুরস্কার হিসেবে দেওয়া হয় ২ লাখ টাকার চেক, সম্মাননাপত্র, সম্মাননা-স্মারক এবং পুষ্পস্তবক।

উৎস: বাংলা একাডেমী ওয়েবসাইট।

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বাংলাদেশ স্বল্পোন্নত দেশের (এলডিসি) তালিকা থেকে উত্তরণ হবে কবে?
  1. ১ নভেম্বর, ২০২৬
  2. ২৪ নভেম্বর, ২০২৬
  3. ২৪ সেপ্টেম্বর, ২০২৬
  4. ২৬ সেপ্টেম্বর, ২০২৬
ব্যাখ্যা

স্বল্পোন্নত দেশ:
- ২০১৮ সালে বাংলাদেশ এলডিসি থেকে উত্তরণপ্রক্রিয়ায় প্রবেশ করে।
- সাধারণত ৬ বছরে এ প্রক্রিয়া শেষ হয়।
- কিন্তু কোভিডের কারণে বাংলাদেশসহ অন্য দেশকে আরও দুই বছর সময় দেওয়া হয়।
- ২০২৬ সালের ২৪ নভেম্বর এলডিসি থেকে বের হবে বাংলাদেশ।
- সম্প্রতি, স্বল্পোন্নত দেশের (এলডিসি) তালিকা থেকে বাংলাদেশের উত্তরণের নির্ধারিত সময়সীমা পিছিয়ে দেওয়ার দাবি তুলেছেন ব্যবসায়ীরা।

উৎস: প্রথম আলো।[লিঙ্ক]

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বাংলাদেশের প্রথম সিমেন্ট কারখানা-
  1. শাহ সিমেন্ট কোম্পানি লিমিটেড
  2. লাফার্জ সুরমা সিমেন্ট কারখানা
  3. ছাতক সিমেন্ট কোম্পানি
  4. মেঘনা সিমেন্ট মিলস লিমিটেড
ব্যাখ্যা

• ছাতক সিমেন্ট কোম্পানী:
- দেশের প্রথম সিমেন্ট কারখানা ছাতক সিমেন্ট কোম্পানি লিমিটেড।
- ছাতক সিমেন্ট কোং লিঃ, সুনামগঞ্জ জেলার ছাতকে অবস্থিত দেশের একমাত্র স্বয়ংসম্পূর্ণ সিমেন্ট কারখানা।
- এটি ১৯৩৭ সনে আসাম বেঙ্গল সিমেন্ট কোম্পানী নামে ব্যক্তি মালিকানায় প্রতিষ্ঠিত।
- ১৯৬৫ সনে পাক-ভারত যুদ্ধের পর ব্যক্তি মালিক কর্তৃক কারখনাটি পরিত্যক্ত হয়।
- পরে ১৯৬৬ সন হতে উহা ইপিআইডিসি'র নিয়ন্ত্রনে আসে।
- বাংলাদেশের স্বাধীন হওয়ার পর প্রথমে বিএমওজিসি, বিএমইডিসি ।
- এবং সর্বশেষ ১৯৮২ সালের ১লা জুলাই থেকে বিসিআইসি'র নিয়ন্ত্রণে আসে।

অপরদিকে,
- লাফার্জ সুরমা সিমেন্ট কারখানা:
- ছাতক লাফার্জ সুরমা সিমেন্ট ফ্যাক্টরি বাংলাদেশে তথা এশিয়া মহাদেশের অন্যতম মাল্টি-ন্যাশনাল কোম্পানি।
- ২০০০ সালের পর উক্ত কোম্পানি টি প্রতিষ্ঠিত হয়

উৎস: বাংলাদেশ কেমিক্যাল ইন্ডাস্ট্রিজ কর্পোরেশন।

.
গৌড়ের ’ছোট সোনামসজিদ' কার শাসনামালে নির্মিত হয়েছিল?
  1. ফকরুদ্দিন মোবারক শাহ
  2. নুসরাত শাহ
  3. আলাউদ্দিন হুসেন শাহ
  4. ইলিয়াস শাহ
ব্যাখ্যা

ছোট সোনামসজিদ:
- গৌড় শহরের দক্ষিণ প্রান্তে বর্তমান ফিরোজাবাদ গ্রামে 'ছোট সোনামসজিদ' নির্মিত হয়েছিল।
- এ মসজিদটি ছিল আকারে ছোট। তবে এ মসজিদেও সোনালি রঙের গিলটির কারুকার্য ছিল।
- সম্ভবত এ কারণেই এটি ছোট সোনা মসজিদ নামে পরিচিত।
- আলাউদ্দিন হুসেন শাহের আমলে জনৈক ওয়ালি মুহাম্মদ এটির নির্মাতা ছিলেন।

উল্লেখ্য,
- বড় সোনা মসজিদের আর এক নাম 'বারোদুয়ারী মসজিদ'।
- এতে বৃহৎ বারোটি দরজা ছিল। এ মসজিদে সোনালি রঙের গিলটি করা কারুকার্য ছিল।
- সম্ভবত এজন্যই এটি সোনা মসজিদ নামে অভিহিত হতো। এ মসজিদটি গৌড়ের বৃহত্তম মসজিদ।
- আসাম বিজয়কে স্মরণীয় করে রাখার জন্য হুসেন শাহ এ মসজিদটি নির্মাণ করেছিলেন।
- ১৫২৭ সালে নসরত শাহ এর নির্মাণ কাজ শেষ করেন।

উৎস: বাংলাদেশের ইতিহাস ও বিশ্বসভ্যতা, নবম-দশম শ্রেণি।

১০.
’’আমার ভাইয়ের রক্তে রাঙানো একুশে ফেব্রুয়ারি’’ গানটির বর্তমান সুরকার কে?
  1. আব্দুল লতিফ
  2. প্রিন্স মাহমুদ
  3. আব্দুর জব্বার
  4. আলতাফ মাহমুদ
ব্যাখ্যা

একুশে ফেব্রুয়ারি গান:
- ’’আমার ভাইয়ের রক্তে রাঙানো একুশে ফেব্রুয়ারি”
- গানটির বর্তমান সুরকার- আলতাফ মাহমুদ।
- গানটির রচয়িতা আবদুল গাফ্ফার চৌধুরী।
- এই গানটি প্রথম হাসান হাফিজুর রহমান সম্পাদিত 'একুশে ফেব্রুয়ারি' (১৯৫৩) গ্রন্থে সংকলিত হয়।
- গানটির প্রথম সুরকার ছিলেন আবদুল লতিফ।
- ঢাকা কলেজের নতুন নতুন ছাত্র ইউনিয়নের অভিষেক অনুষ্ঠানে গানটি প্রথম গাওয়া হয়।

উৎস: বাংলাপিডিয়া ও ডেইলী স্টার,।

১১.

  1. - 3
  2. - 1
  3. 3
  4. 1
ব্যাখ্যা

প্রশ্ন:


সমাধান:

১২.
প্রশ্নবোধক স্থানে কোন সংখ্যাটি বসবে?

  1. 112
  2. 104
  3. 84
  4. 92
ব্যাখ্যা

প্রশ্ন: প্রশ্নবোধক স্থানে কোন সংখ্যাটি বসবে?

সমাধান:
(২য় কলাম × ৩য় কলাম) - ১ম কলাম = ৪র্থ কলাম

(6 × 10) - 2 = 60 - 2 = 58
(7 × 11) - 3 = 77 - 3 = 74
(8 × 12) - 4 = 96 - 4 = 92

সুতরাং, প্রশ্নবোধক স্থানে 92 সংখ্যাটি বসবে।

১৩.
Previous Number of (1000)16
  1. (986)16
  2. (FFF)16
  3. (FFFO)16
  4. (1FFF)16
ব্যাখ্যা

Answer: B) (FFF)16
Explanation:

Answer: (FFF)16

১৪.
Which property is used to simplify A+AB=A?
  1. Distributive
  2. Consensus
  3. Absorption
  4. De-Morgan
ব্যাখ্যা

Answer: C) Absorption

Explanation:

Absorption Law: A+AB=A
Reduces redundant terms in SOP/POS.

১৫.
Find Boolean expression from truth table:

  1. A′B′C+A′BC′+AB′C+ABC
  2. (A+B+C)(A+B′+C′)(A′+B+C′)(A′+B′+C)
  3. Both A & B
  4. None
ব্যাখ্যা

সঠিক উত্তর: খ) (A+B+C)(A+B′+C′)(A′+B+C′)(A′+B′+C)
অপশন–ক-তে একটি টার্ম ভুল আছে: AB′C লেখা হয়েছে, কিন্তু হওয়া উচিত AB′C′.
উত্তরপত্রের ইনপুট পরিবর্তন করা হয়েছে। 
------------- 

Write minterms
Rule for minterm:
For F=1 row, the minterm is an AND of all variables:

If variable = 1 → write uncomplemented (A)
If variable = 0 → write complemented (A')
Check each row:

Row: 0 0 1 → A=0, B=0, C=1 → minterm = A′B′CA'B'CA′B′C
Row: 0 1 0 → A=0, B=1, C=0 → minterm = A′BC′A'BC'A′BC′
Row: 1 0 0 → A=1, B=0, C=0 → minterm = AB′C′AB'C'AB′C′
Row: 1 1 1 → A=1, B=1, C=1 → minterm = ABCABCABC

Step 3: SOP expression
SOP = Sum (OR) of all midterms:

F(A,B,C)=A′B′C+A′BC′+AB′C′+ABC

Write maxterms
Rule for maxterm:
For F=0 row, the maxterm is (A + B + C) but complemented as per 0 → 1:

If variable = 0 → write as uncomplemented (A)
If variable = 1 → write as complemented (A')
Check each row:

Row: 0 0 0 → A=0, B=0, C=0 → maxterm = (A + B + C)
Row: 0 1 1 → A=0, B=1, C=1 → maxterm = (A + B' + C')
Row: 1 0 1 → A=1, B=0, C=1 → maxterm = (A' + B + C')
Row: 1 1 0 → A=1, B=1, C=0 → maxterm = (A' + B' + C)

Step 3: POS expression
POS = Product (AND) of all maxterms:

F(A,B,C) =(A+B+C)(A+B′+C′)(A′+B+C′)(A′+B′+C)

So , Both are Correct

১৬.
Which of the following circuits is a combinational circuit?
  1. Flip-flop
  2. Counter
  3. Full adder
  4. SR latch
ব্যাখ্যা

Answer: C) Full adder

Explanation:

Combinational → output depends only on current input.
Sequential → output depends on input + previous state.
Full adder → combinational Circuit

১৭.
Identified the simplified and equivalent Boolean expression for the following K-map.

  1. BD'
  2. 0
  3. B
  4. D
ব্যাখ্যা

Answer: C) B
Explanation:

We know,
In K - map, a group of nm cells eliminates m variables in given expression
here, we made a group of 8 or 23 cells So 3 variables will be eliminated.

now from K-map , We see that Only B is common within the group
So, Simplified expression is = B

১৮.
A 2-to-4 decoder can be built using how many NOT and AND gates?
  1. 2 NOT and 4 AND
  2. 4 NOT and 2 AND
  3. 2 AND only
  4. 4 OR and 2 NOT
ব্যাখ্যা

Answer: A

Explanation:

Decoder is a combinational circuit that converts binary code or binary information into human understandable format.

Characteristics of Decoder:
It has ‘n’ input lines and maximum of 2n output lines.
It performs the reverse operation of Encoder.
At any time, only one of outputs can be ‘1’ and rest of the outputs are zero(0).
It is used in output system like display units.
2-to-4 Line Decoder:
Let 2 to 4 Decoder has two inputs X & Y and four outputs D0, D1, D2 & D3. The block diagram of 2 to 4 decoder is shown in the following figure-

→ Needs 2 inverters (NOT) for X′, Y′ and 4 AND gates for each output.

১৯.
To construct a 16:1 MUX using 4:1 MUX, how many 4:1 MUXes are needed?
  1. 2
  2. 3
  3. 4
  4. 5
ব্যাখ্যা

Answer: D) 5
Explanation:
In general, to implement B : 1 MUX using A : 1 MUX , one formula is used to implement the same.
B / A = K1,
K1/ A = K2,
K2/ A = K3

KN-1 / A = KN = 1 (till we obtain 1 count of MUX).

And then add all the numbers of MUXes = K1 + K2 + K3 + .... + K N .
To implement 16 : 1 MUX using 4 : 1 MUX
Using the above formula, we can obtain the same.
16 / 4 = 4
4 / 4 = 1 (till we obtain 1 count of MUX)
Hence, total number of 4 : 1 MUX are required to implement 16 : 1 MUX = 4 + 1 = 5.


To implement 64 : 1 MUX using 4 : 1 MUX
Using the above formula, we can obtain the same.
64 / 4 = 16
16 / 4 = 4
4 / 4 = 1 (till we obtain 1 count of MUX)
Hence, total number of 4 : 1 MUX are required to implement 64 : 1 MUX = 16 + 4 + 1 = 21.

২০.
A T flip-flop toggles its state when:
  1. T = 0
  2. T = 1
  3. Clock = 0
  4. Both inputs = 1
ব্যাখ্যা

Answer: B) T = 1
T flip-flop changes state on every clock edge when T=1.

২১.
A counter that returns to zero after counting to a maximum is called:
  1. Ring counter
  2. Johnson counter
  3. Modulo counter
  4. Up/Down counter
ব্যাখ্যা

Answer: C) Modulo counter

Explanation:
Step 1: Understanding what the question means
"A counter that returns to zero after counting to a maximum"

means:

· It counts sequentially from 0 → 1 → 2 → ... → (N−1),

· then resets back to 0 and repeats.

This “wrap-around” behavior is exactly the definition of a modulo counter (Mod-N counter).

A Mod-N counter is a digital counter that goes through N distinct states (from 0 up to N−1) before resetting to zero.
Examples:
Mod-2 counter: counts 0,1 → resets to 0
Mod-10 counter: counts 0–9 (used in digital clocks, called decade counter)
Mod-16 counter: counts 0–15, common in binary systems
When it reaches its maximum count (N−1), it automatically rolls over (returns to 0).
So:
After max → resets to 0 automatically → repeats the cycle.
This matches the question description perfectly.
Others option:
A) Ring Counter
→A type of shift register counter.
→Circulates a single '1' (or '0') through flip-flops.
→Has N states if it has N flip-flops, but doesn’t count in binary sequence.
→It doesn’t “count to a maximum number” — it rotates a bit pattern.
Not a Modulo binary counter.

B) Johnson Counter (Twisted Ring Counter)
→ Similar to ring counter but with feedback of the inverted output.
→Goes through 2N states for N flip-flops.
→Also doesn’t count in binary; it produces a Gray-like sequence.
Not a Modulo binary counter either.

D) Up/Down Counter
→Can count up or down depending on control input.
→It still may be a Mod-N counter, but the term “up/down” only describes direction — not the automatic return to zero.
The question asks about returning to zero after maximum, not about counting direction.

২২.
CMOS advantage over TTL:
  1. Faster
  2. Simpler
  3. More current drive
  4. Higher noise immunity and low power
ব্যাখ্যা

Answer: D) Higher noise immunity and low power

Explanation:


1) CMOS vs TTL basics
TTL (Transistor-Transistor Logic): Uses bipolar junction transistors (BJTs) for both logic gates.

CMOS (Complementary MOS): Uses complementary pairs of MOSFETs (PMOS and NMOS) in each gate.


২৩.
"function overloading" in programming?
  1. Using too many functions in a program
  2. Using functions without any parameters
  3. Creating a function with too many lines of code
  4. Defining multiple functions with the same name but different parameters
ব্যাখ্যা

Answer: D) Defining multiple functions with the same name but different parameters
Explanation:

1) Definition of Function Overloading

Function overloading is a feature in many programming languages (like C++, Java, Python (limited via default args)) that allows multiple functions to have the same name, but with different parameter lists (different number or types of arguments).

It helps to increase code readability, reusability, and flexibility — because you can perform similar operations with different data types or argument counts under one common function name.

2) Example in C++
#include <iostream>
using namespace std;

void add(int a, int b) {
cout << "Sum (int): " << a + b << endl;
}

void add(double a, double b) {
cout << "Sum (double): " << a + b << endl;
}

void add(int a, int b, int c) {
cout << "Sum (three int): " << a + b + c << endl;
}

int main() {
add(2, 3); // Calls add(int, int)
add(2.5, 3.5); // Calls add(double, double)
add(1, 2, 3); // Calls add(int, int, int)
}


Output:

Sum (int): 5
Sum (double): 6
Sum (three int): 6


All three functions are named add, but the compiler automatically chooses the correct one based on the number and type of arguments.

২৪.
What will be the final value of x in the following C code?
#include
void main()
{
int x = 5 * 9 / 3 + 9;
}
  1. 3.75
  2. Depends on compiler
  3. 24
  4. 3
ব্যাখ্যা

Answer: C
Explanation: The * and / have the same precedence so associatively.
Then” 5 * 9 / 3 + 9” evaluate as,
5 * 9 is 45 => 45 / 3 + 9
45 / 3 is 15 => 15 + 9
15 + 9 is 24
Hence 24 is the final answer

২৫.
Which function compares two strings in C?
  1. strcpy()
  2. strcmp()
  3. strcat()
  4. strlen()
ব্যাখ্যা

Answer: B) strcmp()
Explanation:

strcmp(s1, s2)

Compares two strings lexicographically (dictionary order).

Returns:
0 → if both strings are equal.

<0 → if s1 < s2.

>0 → if s1 > s2.

strcpy → Copy
strcmp → Compare
strcat → Concatenate
strlen → Length

২৬.
What is output?
int a = 1;
printf("%d", !a++);
  1. 0
  2. 1
  3. Compiler error
  4. Undefined
ব্যাখ্যা

Answer: a) 0

Trap Explanation:

· a++ (post increment) → value used = 1, then a=2.

· !1 = 0.

২৭.
Which statement skips the current iteration and jumps to the next iteration of the loop?
  1. continue
  2. skip
  3. next
  4. ignore
ব্যাখ্যা

Answer: A) continue

Explanation:

In C (and most programming languages like C++, Java, Python), the continue statement is used inside loops (for, while, do-while) to skip the rest of the current iteration and jump to the next iteration of the loop.

How continue Works

When the continue statement executes:

The remaining statements in the current loop body are skipped.

The control jumps back to the loop’s condition check (in while/do-while) or to the update expression (in for loop).

The loop then continues with the next iteration, if the loop condition is still true.

Example (using for loop)
#include <stdio.h>
int main() {
for (int i = 1; i <= 5; i++) {
if (i == 3)
continue; // skip iteration when i = 3
printf("%d ", i);
}
return 0;
}

Output:
1 2 4 5
Explanation:
When i = 3, the continue statement is executed.
It skips the printf() statement for that iteration.
The loop then moves on to the next iteration (i = 4).

Difference between break and continue
Keyword →→→→→Meaning →→→→→→→→→→→Effect
break →→→ Terminates the entire loop→→ Exits the loop completely
continue→→ → Skips current iteration →→→ Moves to next iteration

২৮.
What is the main purpose of inheritance in OOP?
  1. To allow code reusability
  2. To hide data
  3. To overload operators
  4. To define new data types
ব্যাখ্যা

Answer: A) To allow code reusability

What is Inheritance?

Inheritance is one of the core principles of Object-Oriented Programming (OOP).
It allows a new class (child/derived class) to acquire the properties and behaviors (data members and member functions) of an existing class (parent/base class).
This means that the derived class does not need to rewrite the code already written in the base class — it can reuse and extend it.

Purpose of Inheritance → Code Reusability
The main goal of inheritance is to reuse existing code.
It helps in avoiding redundancy and promotes maintainability.
The derived class can add new features or override existing ones while keeping the old behavior intact.

২৯.
What is the advantage of a circular queue over a simple array queue?
  1. Less memory
  2. Faster enqueue
  3. Avoids overflow when there is free space
  4. Simpler implementation
ব্যাখ্যা

Answer: C
Explanation:

Simple Array Queue Problem:

In a linear array-based queue, once the rear pointer reaches the end of the array, no more insertions can be made, even if there is free space at the beginning (due to dequeues).
Example:
Queue size = 5
Elements dequeued from the front → empty slots form at the beginning.
Rear is at end → still shows "overflow" even though space exists.

Circular Queue Solution:
In a circular queue, the queue is treated as circular (last index connects back to the first).
So, if space is available at the beginning (because some elements were dequeued), Circular queues reuse empty slots by connecting end → beginning.
This avoids false overflow and utilizes memory efficiently.

In short:

Simple queue wastes space after several dequeues.
Circular queue reuses space efficiently.
That’s why the advantage = avoids overflow when free space is available

৩০.
Which of the following is not a valid operation in a Binary Search Tree (BST)?
  1. Sorting elements
  2. Searching for an element
  3. Inserting a new element
  4. Deleting an existing element
ব্যাখ্যা

Answer: A) Sorting elements
Explanation:
Valid operations in BST:

1. Searching for an element

Primary use of BST.

Uses the property: Left subtree < Root < Right subtree.

Time complexity: O(h), where h = height of tree.

2. Inserting a new element

Place the new element at the correct position (leaf) while maintaining the BST property.

3. Deleting an element

Remove a node while maintaining BST rules
Three cases:
Node is a leaf → delete directly.
Node has one child → replace with child.
Node has two children → replace with inorder predecessor/successor.

Option A) : Sorting elements

A BST can give sorted elements if we perform an inorder traversal.

But “sorting” itself is not an operation defined on BST.

Sorting is an application, not a built-in operation.

The BST doesn’t provide an explicit sort() function — it only supports dynamic set operations.

Final Note :

Valid BST operations: Insert, Search, Delete, Traverse.

Sorting is not a direct operation, though inorder traversal yields sorted order.

৩১.
Which type of linked list allows traversal from both directions?
  1. Singly linked list
  2. Doubly linked list
  3. Circular linked list
  4. Self-referential linked list
ব্যাখ্যা

Answer: B) Doubly linked list
Explanation:

Option A) Singly linked list
Each node has data and a single pointer → points to the next node only.
Traversal is one-way only (forward direction). Cannot traverse both ways.

Option B) Doubly linked list
→Data
→Pointer to next node
→Pointer to previous node

This allows movement in both directions:
Forward
: using next pointer.
Backward: using previous pointer.
Supports two-way traversal

Option C) Circular linked list
→Last node connects back to the first node (circular connection).

→Can be singly circular (only forward traversal) or doubly circular (both directions).

Option D) Self-referential linked list

A general concept where a structure contains a pointer to itself (used in all linked lists).
Not specifically both-way traversal.

NOTE:
Singly LL → one way.

Doubly LL → two ways (correct answer).

Circular LL → wraps around but usually one way.

Self-referential → just the general pointer structure.

৩২.
What is the height of a complete binary heap with n nodes?
  1. ⌈log₂(n + 1)⌉
  2. ⌈log₂(n)⌉
  3. ⌈n / 2⌉
  4. log₂(n) + 1
ব্যাখ্যা

Answer: B) ⌈log₂(n)⌉
Explanation
1. Height of a binary tree:
Height = number of edges on the longest path from root to a leaf.
In a complete binary heap, nodes are filled level by level (except possibly the last).
2. Relationship between nodes and height
At height h, the maximum number of nodes = 2(h+1) - 1.
At height h, the minimum number of nodes = 2h.
So if a heap has n nodes:


2h ≤ n ≤ 2(h+1) - 1
Take log₂:
h ≤ log₂(n) < h + 1

Therefore: h = ⌊log₂(n)⌋

Since some definitions use height as number of levels - 1, many books/formulas also express it as ⌈log₂(n)⌉ for simplicity.
Example
If n = 15 nodes:

log₂(15) ≈ 3.9 → height = ⌊3.9⌋ = 3.
Indeed, a full binary heap of 15 nodes has height = 3.
If n = 16:

log₂(16) = 4 → height = 4.

৩৩.
Hashing is best suited for:
  1. Indexing
  2. Searching
  3. Encryption
  4. Sorting
ব্যাখ্যা

Answer: B) Searching
Explanation

Goal of Hashing: Provide fast search operations (average O(1) time).

Hashing uses a hash function to directly compute the storage location of data → no need for linear or binary search.

This makes hashing ideal for searching large datasets like symbol tables, dictionaries, or databases.

Others option:

A) Indexing → Indexing is database technique (e.g., B-trees), not the same as hashing.

C) Encryption → Encryption secures data, hashing is not primarily encryption (though cryptographic hash functions exist).

D) Sorting → Sorting arranges data in order, hashing does not maintain order.

৩৪.
Which data structure is commonly used to implement Huffman coding efficiently?
  1. Stack
  2. Min-heap
  3. Queue
  4. AVL tree
ব্যাখ্যা

Answer: B) Min-heap
Explanation:

Huffman Coding Overview
Huffman coding is a lossless data compression algorithm.
It works by repeatedly merging two nodes with the smallest frequencies to build a binary tree (Huffman Tree).

2. Why Min-Heap?
At each step, Huffman’s algorithm needs to quickly find the two nodes with the smallest frequency.
A min-heap is a priority queue where:
The root always contains the minimum element.
Insertion and extraction of the minimum element take O(log n) time.

Example:Suppose symbol frequencies: A:5, B:9, C:12, D:13
Build a min-heap with these frequencies: [5, 9, 12, 13]
Extract two smallest (5 and 9) → combine → insert 14 back → min-heap adjusts automatically.
This ensures efficient O(n log n) construction of Huffman tree


A min-heap efficiently extracts two smallest frequency nodes at each step → reduces time complexity to O(n log n).

৩৫.
Which of the following properties are obeyed by all three tree – traversals?
  1. Left subtrees are visited before right subtrees
  2. Right subtrees are visited before left subtrees
  3. Root node is visited before left subtree
  4. Root node is visited before right subtree
ব্যাখ্যা

ANSWER: A
Explanation:
Tree Traversals Overview
Binary tree traversals are methods to visit all nodes:

Preorder: Root → Left Right
Inorder: Left → Root → Right
Postorder: Left Right → Root
In all three traversals, the left subtree is always visited before the right subtree.

when the root is visited:
Preorder → before left subtree
Inorder → between left and right subtree
Postorder → after left and right subtree
Hence, the common property = “left subtree visited before right subtree.”

৩৬.
What is the advantage of Divide and Conquer?
  1. Parallelism
  2. Simplicity
  3. Faster in some cases
  4. All of the above
ব্যাখ্যা

Answer: D) All of the above

Explanation:

Divide and Conquer divides a problem into smaller subproblems, solves them recursively, and combines the results.

Advantages:

Parallelism: Subproblems can be solved independently.

Simplicity: Breaking problems into smaller parts simplifies logic.

Faster in some cases: Recursive breakdown reduces time complexity (e.g., Merge Sort O(n log n) vs Bubble Sort O(n²)).

৩৭.
Which of the following is a classic example of a problem that uses Dynamic Programming for optimization?
  1. Depth-First Search
  2. Binary Search
  3. Quick Sort
  4. Knapsack Problem
ব্যাখ্যা

Answer: D) Knapsack Problem

Explanation:

Dynamic Programming (DP) solves problems with overlapping subproblems and optimal substructure by storing results of subproblems.

The 0/1 Knapsack problem is a classic DP problem: we decide to include/exclude an item to maximize value.

DFS, Binary Search, and Quick Sort don’t need DP.

৩৮.
If an algorithm has running time T(n) = 5n² + 3n + 2, what is its Big-O?
  1. O(n)
  2. O(log n)
  3. O(n³)
  4. O(n²)
ব্যাখ্যা

Answer: D) O(n²)

The highest degree term dominates → n².

Constants (5) and lower terms (3n, 2) are ignored in asymptotic growth

৩৯.
What is the main disadvantage of circuit switching compared to packet switching?
  1. Higher bandwidth utilization
  2. Dedicated path wastes resources
  3. Better reliability
  4. No delay
ব্যাখ্যা

Answer: B
Explanation:
• Circuit switching (Telephone networks): requires a dedicated path, even if no data is sent → wastes bandwidth.
Packet switching (Internet): data broken into packets, efficient resource usage.

৪০.
GSM (2G) primarily uses:
  1. CDMA
  2. TDMA
  3. CSMA/CA
  4. WDM
ব্যাখ্যা

Answer: B) TDMA

Explanation:

GSM (Global System for Mobile Communications) → 2G cellular system.
It uses TDMA (Time Division Multiple Access) to allocate time slots to multiple users.

CDMA (Code Division Multiple Access) is used in some 2G (IS-95) and 3G systems.
CSMA/CA → wireless LAN (Wi-Fi).
WDM → optical fiber communications.

৪১.
A Class C network 192.168.1.0 is subnetted with /28. How many subnets are created?
  1. 4
  2. 8
  3. 16
  4. 32
ব্যাখ্যা

Answer: C) 16

Solution:

· Class C default mask = /24

· New mask = /28 → borrowed bits = 28 – 24 = 4

· Number of subnets = 2borrowed bits=24=16

৪২.
What is the main advantage of ATM switching?
  1. Handles only voice
  2. Handles only data
  3. Can handle voice, video, and data in real-time
  4. Uses variable packet sizes
ব্যাখ্যা

Answer: C

Explanation:

ATM was designed as a unified transport technology:

Can carry voice, video, and data simultaneously.
Fixed cell size ensures low latency.
Unlike IP, which uses variable-length packets, ATM keeps latency predictable.

৪৩.
Which technique is used to ensure confidentiality of data?
  1. Hashing
  2. Encryption
  3. Digital Signature
  4. Intrusion Detection
ব্যাখ্যা

Answer: B
Explanation:

Encryption converts plaintext → ciphertext, so only authorized users can read.
Hashing ensures integrity, not confidentiality.
Digital signatures authenticate sender.

৪৪.
In symmetric key encryption, both sender and receiver use:
  1. Different public keys
  2. Same secret key
  3. One private and one public key
  4. No keys
ব্যাখ্যা

Answer: B

Explanation:

Symmetric encryption (e.g., AES, DES): sender & receiver share the same secret key.
Advantage: fast.
Disadvantage: key distribution problem (how to share securely?).

৪৫.
The maximum distance for UTP without repeaters in Ethernet is:
  1. 50 m
  2. 100 m
  3. 250 m
  4. 1 km
ব্যাখ্যা

Answer: B) 100 m
Explanation:
UTP cables in Ethernet can transmit up to 100 meters reliably.
Beyond this, attenuation and crosstalk degrade the signal.

৪৬.
Wi-Fi (IEEE 802.11) typically works on which frequencies?
  1. 2.4 GHz & 5 GHz
  2. 1 GHz & 10 GHz
  3. 300 MHz & 600 MHz
  4. 10 GHz & 20 GHz
ব্যাখ্যা

Answer: A
Explanation:

Wi-Fi operates on unlicensed ISM bands:

2.4 GHz (longer range, more interference)

5 GHz (higher speed, shorter range).

Latest Wi-Fi 6E adds 6 GHz band.

৪৭.
Which digital modulation is most bandwidth efficient?
  1. ASK
  2. FSK
  3. PSK
  4. AM
ব্যাখ্যা

Answer: C

Explanation:

PSK (esp. QPSK, QAM) is bandwidth efficient because more bits per symbol.

ASK: noise-sensitive.

FSK: requires larger bandwidth.

AM: analog, not efficient.

৪৮.
According to Nyquist-Shannon Sampling Theorem, a signal of maximum frequency fmax must be sampled at:
  1. fmax
  2. 0.5 × fmax
  3. 2 × fmax
  4. 4 × fmax
ব্যাখ্যা

Answer: C

To reconstruct a band-limited signal without aliasing, the sampling rate must be at least twice the highest frequency.

Called Nyquist rate.

Example: Audio frequency 20 kHz → sampled at ≥ 40 kHz (CD audio uses 44.1 kHz).

৪৯.
In Time Division Multiplexing (TDM):
  1. Signals use separate frequency bands
  2. Signals use different time slots
  3. All signals use the same slot
  4. Only analog signals supported
ব্যাখ্যা

Answer: B

TDM assigns time slots to users sequentially.

Synchronous TDM: fixed slots even if idle.

Statistical TDM: slots allocated dynamically → higher efficiency.

৫০.
Which of the following can detect burst errors efficiently?
  1. Parity
  2. Checksum
  3. CRC
  4. Stop-and-wait
ব্যাখ্যা

Answer: C) CRC (Cyclic Redundancy Check)
Explanation:
What is a burst error?
A burst error occurs when two or more bits in a sequence are corrupted.
Example: 1011101 → one or more consecutive bits flipped.

Why CRC is efficient for burst errors:
Cyclic Redundancy Check (CRC) treats data as a polynomial and divides it by a generator polynomial.
The remainder (CRC value) is transmitted along with the data.
At receiver, polynomial division is performed; if remainder ≠ 0 → error detected.
CRC can detect:

All single-bit errors
All double-bit errors
Any odd number of errors (depending on polynomial)
Most burst errors, especially those shorter than the CRC lengt

৫১.
VSAT typical latency (round-trip) is approximately:
  1. 1–5 ms
  2. 50–100 ms
  3. 500–600 ms
  4. 10–20 ms
ব্যাখ্যা

Answer: C) 500–600 ms
Explanation:

GEO satellites → ~36,000 km altitude

Propagation delay → 250–270 ms one-way → 500–540 ms round-trip

Causes slight lag in voice or gaming applications

৫২.
A programmer writes a program to multiply two numbers instead of dividing them by mistake. How can this error be detected?
  1. Compiler or interpreter
  2. Compiler only
  3. Interpreter only
  4. None of the mentioned
ব্যাখ্যা

Answer: D) None of the mentioned
Explanation:
Nature of the Error

→ Writing * instead of / is not a syntax error (grammar is still correct).

→ It’s not a semantic error either (types are still valid — multiplying integers is legal).

It is a logical error → the program runs, but gives wrong output compared to programmer’s intention.

Logical errors like using * instead of / cannot be detected by either compiler or interpreter.

They can only be detected during testing/debugging when the output is checked

৫৩.
Which one of the following is TRUE about DFA and NFA?
  1. Every DFA is also an NFA
  2. Every NFA is also a DFA
  3. NFA can recognize more languages than DFA
  4. DFA requires more states than NFA always
ব্যাখ্যা

Answer: A) Every DFA is also an NFA
• DFA ⊆ NFA in expressive power.
• Both recognize exactly regular languages.
• NFAs can be smaller, but after conversion to DFA, state count may explode (but not always)

৫৪.
Which one of the following statements is FALSE?
  1. Every regular language has its own minimal DFA.
  2. Every NFA can be converted to a PDA of the same size.
  3. Every context-free language's complement is recursive.
  4. Any non-deterministic PDA can be converted to a deterministic equivalent.
ব্যাখ্যা

Answer: (D) Any non-deterministic PDA can be converted to a deterministic equivalent.
Explanation:
Deterministic PDA cannot handle ambiguous languages or grammar, but NDPDA can handle ambiguous languages and any context-free grammar. As a result, no non-deterministic PDA can be converted to a deterministic PDA.

৫৫.
Which type of error can be detected in the semantic analysis phase?
  1. Missing semicolon
  2. Unrecognized keyword
  3. Type mismatch
  4. Misplaced parenthesis
ব্যাখ্যা

Answer: C) Type mismatch

Lexical Analysis: Reads characters and forms tokens (keywords, identifiers, operators).

Detects unrecognized symbols or invalid characters.
Syntax Analysis (Parsing): Checks if tokens form grammatically correct statements.
Detects missing semicolons, misplaced parentheses, syntax violations.

Semantic Analysis: Ensures the meaning of the program is correct.

Checks type consistency, scope rules, function argument matching, and variable declarations.

Semantic errors occur when the structure is correct, but the meaning is wrong.
Example:
int x;
x = "hello"; // Type mismatch: assigning string to int

Syntactically, x = "hello"; is valid (ends with semicolon, valid tokens).
Semantic analysis detects the type mismatch.

Options option:

a) Missing semicolon: Syntax error → detected during parsing.
c) Unrecognized keyword: Lexical error → detected during lexical analysis.
d) Misplaced parenthesis: Syntax error → detected during parsing.

৫৬.
The main goal of code optimization in compilers is:
  1. To reduce the number of tokens
  2. To make code run faster or use less memory
  3. To change program logic
  4. To simplify parsing
ব্যাখ্যা

Answer: B) To make code run faster or use less memory

Explanation:

Optimization improves performance (speed, memory, power consumption).

Must preserve the semantic meaning of the program.

Example: x = 5; y = x * 2; → optimized as y = 10;.

৫৭.
Which of the following is a challenge in code generation?
  1. Register allocation
  2. Lexical analysis
  3. Tokenization
  4. Syntax parsing
ব্যাখ্যা

Answer: A) Register allocation

Explanation:

Limited registers → compiler must allocate variables wisely.

Example: in loops, keep frequently used variables in registers to improve speed.

৫৮.
Pumping Lemma is mainly used for:
  1. Designing regular expressions
  2. Proving a language is not regular
  3. Converting NFA to DFA
  4. Minimizing automata
ব্যাখ্যা

Answer: B) Proving a language is not regular

Explanation:

Pumping Lemma provides a property that all regular languages must satisfy.
If a language violates it, → not regular.
Example: {aⁿ bⁿ | n ≥ 0} fails pumping lemma → not regular.

৫৯.
In 8086 microprocessor, segmentation is used mainly to:
  1. Eliminate registers
  2. Simplify programming
  3. Reduce clock speed
  4. Expand addressable memory
ব্যাখ্যা

Answer: D) Expand addressable memory
Explanation:

8086 is a 16-bit processor → 16-bit registers → max 64 KB memory directly addressable.
But Intel wanted 1 MB memory access.
Solution: Segmentation
Memory divided into segments (Code, Data, Stack, Extra).
Physical Address =Segment Register×16+Offset

Allows 20-bit addresses → 1 MB memory access.

Other options:

A) Eliminate registers → segmentation actually uses more registers
B) Simplify programming → segmentation complicates programming, not simplifies.
C) Reduce clock speed → unrelated.

৬০.
The 8086 uses which type of internal architecture?
  1. Von Neumann architecture
  2. Harvard architecture
  3. Modified Harvard with EU and BIU
  4. RISC architecture
ব্যাখ্যা

Answer: C) Modified Harvard with EU and BIU
Explanation:
8086 split into:
Bus Interface Unit (BIU): Fetches instructions, handles queue (6 bytes prefetch).
Execution Unit (EU): Decodes and executes instructions.
Works like Harvard (separate fetch and execute), but shares same memory.
Key feature: Instruction prefetch → basic pipelining.

৬১.
Which of the following chip provides Programmable parallel I/O ports?
  1. 8237 chip
  2. 8255A chip
  3. 8259A chip
  4. 8253/8254 chip
ব্যাখ্যা

Answer: B) 8255A chip

Explanation:
1. What is 8255A?

Intel 8255A = Programmable Peripheral Interface (PPI) chip. Provides programmable parallel I/O ports for microprocessors like 8085, 8086.

It has 3 ports:
Port A (8-bit)
Port B (8-bit)
Port C (8-bit, split into two 4-bit parts
These ports can be programmed as input or output, depending on the control word written to the control register.

Widely used for interfacing keyboards, LEDs, printers, displays, switches, etc.

8237 → DMA Controller
8255A → I/O interface.
8259A → Interrupt controller.
8253/8254 → Timer/counter.

৬২.
A control hazard arises mainly due to:
  1. Cache misses
  2. Branch and jump instructions
  3. Divide-by-zero
  4. Resource sharing
ব্যাখ্যা

Answer: B
Explain:

What is a Hazard in Pipelining?
In a pipelined CPU, hazards are conditions that prevent the next instruction from executing in the next cycle.
Three major types:

Data Hazard → Dependency on the result of a previous instruction.
Structural Hazard → Hardware resource conflict.
Control Hazard → Arises due to branch/jump instructions.

2. What is a Control Hazard?
Control hazard = Branch hazard.
Happens when the CPU does not know which instruction to fetch next because of a branch or jump decision.
So, Answer: B) Branch and jump instructions

Others option:
Cache misses: his is a memory access delay, not a pipeline control hazard.
Divide-by-zero: This causes an exception/interrupt, not a control hazard.
Resource sharing: This leads to structural hazards, not control hazards.

৬৩.
The control signals in a CPU typically control:
  1. ALU operations
  2. Register transfers
  3. Memory read/write
  4. All of the above
ব্যাখ্যা

Answer: D
Explanation:
Control signals orchestrate all data movement and processing inside CPU. They tell ALU what to compute, which registers to load, and when to read/write memory.

৬৪.
The main advantage of pipelining is:
  1. Increased instruction throughput
  2. Reduced instruction latency
  3. Reduced number of stages in execution
  4. Lower hardware cost
ব্যাখ্যা

Answer: A
Explanation:
• Pipelining allows multiple instructions to overlap in execution.
Latency per instruction doesn’t improve, but overall throughput (instructions per unit time) increases.

৬৫.
A software approach for fault-tolerant computing is:
  1. Triple Modular Redundancy (TMR)
  2. Checkpointing and rollback
  3. ECC memory
  4. Systolic arrays
ব্যাখ্যা

Answer: B) Checkpointing and rollback

Explanation:
1. Fault-tolerant computing basics:
Fault tolerance = ability of a system to continue correct operation even when faults occur.
Approaches can be hardware-based or software-based.

2. Software approachCheckpointing and Rollback
Checkpointing = saving the state of a process/program at certain intervals.
If a fault occurs, the system rolls back to the most recent checkpoint instead of restarting from the beginning.
Example: Long-running computations in distributed systems (like supercomputers).
This is a software-level technique, because the system state management and recovery logic are handled in software, not hardware.

Checkpointing and rollback = software approach to fault tolerance.
TMR, ECC memory, systolic arrays = hardware techniques.

৬৬.
The biggest challenge in parallel processing is:
  1. Higher clock rates
  2. Use of caches
  3. Synchronization and data dependency
  4. Instruction fetch speed
ব্যাখ্যা

Answer: C
Explanation:
• Parallelism suffers from synchronization overhead, communication delays, and dependencies (Amdahl’s law).
• Limits maximum achievable speedup

৬৭.
A Data Dictionary in DBMS is used to:
  1. Store actual data records
  2. Store metadata about data
  3. Perform query optimization
  4. Compress database size
ব্যাখ্যা

Answer: b) Store metadata about data

What is a Data Dictionary?

A data dictionary is like the “catalog” or “blueprint” of a database.

It contains metadata → data about data.

It does not store actual user data (like names, salaries, etc.), but stores:

→Table names

→Column names & data types

→Constraints (Primary Key, Foreign Key, etc.)

→Indexes

→Relationships between tables

→Access permissions

৬৮.
The technique most commonly used to implement virtual memory is:
  1. Paging
  2. Segmentation
  3. Swapping
  4. Both (A) and (B)
ব্যাখ্যা

Answer: D) Both (A) and (B)
Explanation:
Virtual memory can be implemented by paging (fixed-size blocks) or segmentation (variable-size).
In modern OS, paging (sometimes segmentation + paging) is dominant.

(C) Swapping is process-level, not directly VM implementation

৬৯.
In relational model, a tuple refers to:
  1. A row
  2. A column
  3. A constraint
  4. A file
ব্যাখ্যা

Answer: A
Explanation:

Table = Relation.
Row = Tuple.
Column = Attribute

৭০.
Which of the following is an example of a functional dependency?
  1. Roll_No → Student_Name
  2. Roll_No ↔ Student_Name
  3. Student_Name → Roll_No
  4. Roll_No = Student_Name
ব্যাখ্যা

Answer: A) Roll_No → Student_Name
Explain:
Functional dependency in a database management system (DBMS) defines a relationship between attributes in a table, where one attribute uniquely determines another. It is denoted as X → Y, meaning the value of attribute X determines the value of attribute Y.

Roll_No uniquely determines Student_Name.
Functional dependency is always one-way (not necessarily reversible)

৭১.
In Dense Indexing, an index entry is created for:
  1. Every block of records
  2. Every record
  3. Only primary keys
  4. Every file
ব্যাখ্যা

Answer: B) Every record

Dense Index
In a dense index, a record is created for every search key valued in the database. This helps you to search faster but needs more space to store index records. In this Indexing, method records contain search key value and points to the real record on the disk.
Pros: Fast search.
Cons: Large index size, high maintenance overhead.


Sparse Index: Index has one entry per block of records, smaller but slower for search.

৭২.
3NF (Third Normal Form) eliminates:
  1. Partial dependency
  2. Transitive dependency
  3. Multivalued dependency
  4. Redundant keys
ব্যাখ্যা

Answer: B) Transitive dependency
Explain:
Definitions of normal forms:

1NF (First Normal Form) →All attributes are atomic (no repeating groups or multivalued attributes).
2NF (Second Normal Form)
Relation is in 1NF.
→No partial dependency → no non-key attribute depends on part of a composite primary key.
3NF (Third Normal Form)
→Relation is in 2NF.
→No transitive dependency → non-key attribute must depend only on the primary key, not on another non-key attribute.

BCNF (Boyce–Codd Normal Form) →Even stricter: for every functional dependency X → Y, X must be a super key.

Transitive Dependency:
Definition: A non-key attribute depends on another non-key attribute instead of directly on the primary key.
Example Table:
Student(RollNo, DeptID, DeptName)
RollNo → DeptID
DeptID → DeptName
⇒ RollNo → DeptName (through DeptID) = transitive dependency

Why 3NF Eliminates Transitive Dependency:
In 3NF, all non-key attributes must depend directly on the key.
To fix the above example:
Split into two relations:
Student(RollNo, DeptID)
Department(DeptID, DeptName)

Now,
RollNo → DeptID (direct)
DeptID → DeptName (direct in another relation)
This removes redundancy and anomalies.

৭৩.
In cost estimation, selectivity of selection is defined as:
  1. Fraction of tuples that satisfy selection condition
  2. Ratio of attributes accessed to total attributes
  3. Number of disk blocks used for selection
  4. Ratio of keys to foreign keys
ব্যাখ্যা

Answer: A) Fraction of tuples that satisfy selection condition
Explanation:

Selectivity = (Result size) ÷ (Total relation size). Lower selectivity → fewer tuples returned → cheaper.

৭৪.
Which command is used to remove specific rows from a table?
  1. DROP
  2. TRUNCATE
  3. DELETE
  4. CLEAR
ব্যাখ্যা

Answer: C) DELETE
Explanation:

DELETE is a DML (Data Manipulation Language) command used to remove specific rows from a table based on a condition.

Syntax:

DELETE FROM Students WHERE Age < 18;
Only rows satisfying the WHERE condition are deleted.
If WHERE is omitted, all rows are deleted, but table structure remains.

DELETE (DML)→ selective row removal.
TRUNCATE (DDL) → removes all rows fast.
DROP (DDL) → deletes the table entirely.
CLEAR→ NOT valid SQL command

৭৫.
Which SQL command is used to combine rows from two tables based on related columns?
  1. UNION
  2. INTERSECT
  3. JOIN
  4. CONNECT
ব্যাখ্যা

Answer: C) JOIN

JOIN connects tables using keys.
Example:
· SELECT Orders.order_id, Customers.name

· FROM Orders

· JOIN Customers ON Orders.customer_id = Customers.id;

UNION combines results vertically.
INTERSECT finds common rows

৭৬.
In which mode are most application programs executed?
  1. Kernel Mode
  2. User Mode
  3. Privileged Mode
  4. Supervisor Mode
ব্যাখ্যা

Answer: B) User Mode
Explanation

User Mode is the CPU mode in which regular application programs run.

Characteristics:

Restricted access to hardware and critical system resources.

Cannot execute privileged instructions (like I/O or memory management) directly.

Any request for system resources is made via system calls, which temporarily switch the CPU to kernel mode.

Examples:
Word processors, web browsers, media players all execute in user mode.

Key Point:

User mode = safe execution for applications

Kernel mode = full access for OS services

৭৭.
Which type of OS is mostly used in embedded systems like pacemakers?
  1. Batch OS
  2. Time-Sharing OS
  3. Distributed OS
  4. Real-Time OS
ব্যাখ্যা

Answer: D) Real-Time OS
Explanation
Real-Time Operating System (RTOS) is designed to guarantee predictable and deterministic response times.
Embedded systems, like pacemakers, industrial robots, and avionics, require that the OS responds within strict deadlines.
Key Features of RTOS for Embedded Systems:

→Deterministic timing – tasks execute within guaranteed deadlines.
→Fast context switching – critical for handling multiple time-sensitive tasks.
→Minimal latency – ensures hardware responses happen on time.
→Reliability and fault tolerance – essential for life-critical applications like pacemakers.

Why not the others?
A) Batch OS → Executes jobs sequentially without interaction; not suitable for real-time.
B) Time-Sharing OS → Provides interactive response but cannot guarantee strict timing.
C) Distributed OS → Manages multiple machines as a single system; irrelevant for small embedded devices.


Embedded systems = real-time response critical → RTOS is required

৭৮.
Which scheduling algorithm minimizes the average waiting time?
  1. Shortest Job First (SJF)
  2. FCFS
  3. Round-Robin
  4. Priority
ব্যাখ্যা

Answer: A) Shortest Job First (SJF)
Explanation:
1. What is SJF Scheduling?
Shortest Job First (SJF) schedules the process with the shortest CPU burst time next.
Can be non-preemptive (once a process starts, it runs to completion) or preemptive (Shortest Remaining Time First, SRTF).

2. Why SJF Minimizes Average Waiting Time
Average waiting time (AWT) is the mean time a process spends in the ready queue before execution.
By executing short processes first, longer processes do not block multiple short processes.
This reduces total waiting time for all processes.

Example:
Processes with CPU bursts: P1=2, P2=4, P3=6 (time units)
FCFS order: P1 → P2 → P3

Waiting times: P1=0, P2=2, P3=6 → Avg = 2.67
SJF order: P1 → P2 → P3 (already sorted, same in this case)
If bursts were unsorted, SJF always optimizes AWT.
Key Point:
SJF =
Optimal scheduling algorithm for minimizing average waiting time when CPU burst times are known.
Drawback:
Can cause starvation for long processes.

৭৯.
Working set model helps in:
  1. Preventing deadlock
  2. Avoiding thrashing
  3. Reducing context switch
  4. Increasing page size
ব্যাখ্যা

Answer: B) Avoiding thrashing
Explanation
1. What is the Working Set?
The working set of a process is the set of pages actively used by the process during a certain period of execution.
Denoted as W(t, Δ), where Δ is the time window.
Idea: If all pages in the working set are in memory, the process executes efficiently with minimal page faults.

2. How the Working Set Model Prevents Thrashing
Thrashing occurs when the sum of working sets of all processes exceeds physical memory, causing excessive page faults.
Working set model approach:
OS tracks the working set of each process
→Ensures enough frames are allocated to hold the working set
→Only loads processes whose working set can fit → prevents thrashing
This ensures processes run efficiently without constant paging.
Key Point:
Working set = actively used pages of a process
Goal: Keep the working set in memoryavoid thrashing

৮০.
Which is more efficient in resource utilization?
  1. Multiprocessing
  2. Multithreading
  3. Both equal
  4. None
ব্যাখ্যা

Answer: B) Multithreading

Why Multithreading is More Efficient
Threads within the same process share data and resources → no need to allocate separate memory for each thread.
Context switching between threads is faster than switching between processes.
CPU utilization improves because threads can execute while others are waiting (e.g., I/O operations).

৮১.
Which one is not a security threat to OS?
  1. Trojan horse
  2. Worm
  3. Deadlock
  4. Virus
ব্যাখ্যা

Answer: C) Deadlock
Explanation:

Deadlock = resource allocation issue, not a security threat.
Trojan, Worm, Virus = malicious security threats.

৮২.
Which of the following represents a major risk in software project management?
  1. Poor estimation of project cost and schedule
  2. Ambiguous or changing user requirements
  3. Lack of top management support
  4. All of the above
ব্যাখ্যা

Answer: D) All of the above
Explanation:

A) Poor estimation of project cost and schedule
One of the most frequent risks.
Leads to cost overrun, missed deadlines, and scope reduction.
Root cause: inaccurate requirements, lack of metrics, or over-optimism.

B) Ambiguous or changing user requirements
Known as requirements volatility.
Causes scope creep, rework, and delays because the target keeps changing.
Often arises from poor communication with clients or unclear vision.

C) Lack of top management support
Without executive backing, teams may face budget cuts, resource shortages, and low morale.
Also weakens decision-making and project prioritization.
All three contribute to project risk, hence the best answer is (d) All of the above.


Key Concept:
In software project management, risk categories typically include:

Project risks → Cost, schedule, resource, and planning failures.
Technical risks → Technology limitations, integration issues, performance problems.
Business risks → Changing user needs, budget issues, or organizational instability.
Good managers identify, analyze, and mitigate these risks early through proper risk management planning.

৮৩.
Which diagram is used for data modeling?
  1. ER Diagram
  2. Sequence Diagram
  3. State Diagram
  4. Context Diagram
ব্যাখ্যা

Answer: A) ER Diagram (Entity–Relationship Diagram)
Explanation:

What is an ER Diagram?
An Entity–Relationship (ER) Diagram) is a data modeling technique used to visually represent:

Entities → real-world objects or concepts (like Student, Course, Employee)

Attributes → properties of entities (like Name, ID, Salary)

Relationships → how entities are connected (like enrolls in, manages, teaches)

In other words, ER diagrams model how data is stored, related, and organized within a system — forming the foundation for database design.

Purpose of ER Diagrams

Define data structure clearly before implementation.

Show relationships among entities (one-to-one, one-to-many, many-to-many).

Help transform the conceptual model into a relational database schema.

Example:
A simple Student–Course ER Diagram:

[STUDENT] ──<enrolls>── [COURSE]


Here:

Entities: STUDENT, COURSE

Relationship: enrolls

Attributes: Student_ID, Student_Name, Course_ID, Course_Name

৮৪.
Which Object-Oriented Design (OOD) concept allows an object to take multiple forms?
  1. Encapsulation
  2. Inheritance
  3. Polymorphism
  4. Aggregation
ব্যাখ্যা

Answer: C) Polymorphism
Explanation:
A) Encapsulation: Data hiding, not multiple forms.
B) Inheritance: Enables hierarchy and reuse, but not multiple forms by itself.
C) Polymorphism: Allows objects to respond differently to the same message depending on their type. Example: method overriding in subclasses. (Correct)
D) Aggregation: Represents “has-a” relationships, unrelated to polymorphism

৮৫.
Critical systems require:
  1. Minimal documentation
  2. High dependability and fault tolerance
  3. Rapid delivery
  4. No requirement analysis
ব্যাখ্যা

Answer: B) High dependability and fault tolerance
Explanation

What Are Critical Systems?

A critical system is one where failure can lead to serious consequences, such as:

→Loss of life (e.g., medical, aviation, or nuclear control systems)

Major financial loss (e.g., banking or stock trading systems)

→Environmental damage (e.g., chemical plant monitoring systems)

Hence, these systems must operate reliably and safely under all conditions So, High Dependability and Fault Tolerance is required in Critical system

Critical systems are designed with dependability as their top priority.

Dependability includes several key attributes:

Reliability → System performs its function correctly and continuously.

Availability → System remains operational with minimal downtime.

Safety → System operates without causing unacceptable harm.

Security → Protection from unauthorized access or malicious actions.

Maintainability → Faults can be detected and repaired quickly.

Fault Tolerance ensures that even when part of the system fails, it can continue functioning correctly (e.g., redundant components, backup systems, error detection and recovery mechanisms).

Example:

An Aircraft control system must keep functioning even if one sensor or processor fails.

A hospital ventilator system must remain reliable during power interruptions — using backup circuits.

৮৬.
Which of the following is not a fault-tolerant technique?
  1. Recovery blocks
  2. N-version programming
  3. Exception handling
  4. Waterfall development
ব্যাখ্যা

Answer: D) Waterfall development
Explanation:

Waterfall is a development methodology, NOT a fault-tolerance technique.

The others are explicitly designed to detect, mask, or recover from faults.

৮৭.
Which activity in maintenance involves modifying software to improve performance or maintainability?
  1. Corrective
  2. Adaptive
  3. Perfective
  4. Preventive
ব্যাখ্যা

Answer: C

Explanation:

A) Corrective: Fixes defects, not performance improvements.
B) Adaptive: Adjusts to new environments or platforms.
C) Perfective: Focuses on enhancing software features, performance, readability, and maintainability after delivery. (Correct.)
D) Preventive: Avoids future problems but not specifically improving performance.

৮৮.
Which of the following best describes Agile software development?
  1. Sequential development with heavy documentation
  2. Iterative, incremental, with strong user involvement
  3. Risk-driven model only for large projects
  4. No testing until completion
ব্যাখ্যা

Answer: B) Iterative, incremental, with strong user involvement

Explanation
What Is Agile Software Development?

Agile is a software development methodology that emphasizes:

Iterative and incremental development – the product is built in small, manageable pieces.

Customer collaboration – continuous involvement of users/stakeholders to refine requirements.

→Flexibility and adaptability – changes are welcomed even late in development.

→Working software over comprehensive documentation – focus on delivering functional code.

Agile Manifesto Principles:

→Individuals and interactions over processes and tools

→Working software over comprehensive documentation

→Customer collaboration over contract negotiation

→Responding to change over following a plan

৮৯.
Which technique can be used to perform formal verification?
  1. Code walkthroughs
  2. Model checking
  3. User surveys
  4. Unit testing
ব্যাখ্যা

Answer: B) Model Checking (most standard technique)

Explanation
What Is Formal Verification?
Formal verification is the process of proving or disproving the correctness of a system’s design or program with respect to a formal specification using mathematical and logical methods.

Goal: Ensure that the system behaves exactly as intended and satisfies all requirements.
Especially important for critical systems (aircraft, medical devices, nuclear plants) where errors are unacceptable.

Common Techniques for Formal Verification
→Model Checking
→Theorem Proving
→Abstract Interpretation

Analyzes program properties using approximate models to detect potential errors like buffer overflows, deadlocks, or race conditions.

A) Code walkthroughs: Informal verification, not formal.
C) User surveys: Validation tool, not formal verification.
D) Unit testing: Dynamic verification, not formal.

৯০.
Which of the following best differentiates Alpha and Beta testing?
  1. Alpha testing is performed by developers, Beta by end users
  2. Alpha and Beta are both performed after deployment
  3. Alpha tests usability only; Beta tests functionality only
  4. There is no difference between Alpha and Beta testing
ব্যাখ্যা

Answer: A) Alpha is performed by developers; Beta by end users
Explanation:

The key distinction lies in who performs the testing and where it’s done.

Alpha:
→By developers/testers at developer site
→Controlled environment

Beta:
→By actual users at user site
→Real environment, realistic feedback

Other options:

b) Both after deployment → They occur before final release.
c) Alpha tests usability only → Alpha tests both functionality and usability.
d) No difference →They differ in purpose, performers, and environment.

৯১.
In software cost estimations, Halstead metrics measure --
  1. Software reliability
  2. Code complexity and volume
  3. Project cost only
  4. Team productivity
ব্যাখ্যা

Answer: B)
Explanation

Halstead’s Software Science Metrics
Developed by: Maurice H. Halstead (1977)
Purpose: To measure software complexity, volume, and effort based on operators and operands in the source code.
Key Concepts:
n1​: number of distinct operators
n2​: number of distinct operands
N1​: total number of operators
N2​: total number of operands
Volume (V):
V=(N1+N2) × log⁡2(n1+n2)
Effort (E):
E=V/S where
S = “programmer’s ability” factor.
Use: Measures code complexity, effort to implement or understand, and sometimes potential number of bugs.

৯২.
Which of the following is a tautology?
  1. p∧¬p
  2. p∧q
  3. p∨q
  4. p∨¬p 
ব্যাখ্যা

Answer: D) p∨¬p

Explanation:

A tautology is a statement that is true for all truth values of its variables.

For any proposition p:
if p is true → p∨¬p=T∨F=T.

If p is false → F∨T=T.

So, it is always true.

Others option:

A) p∧¬p → always false (contradiction).
B) p∧q → not always true; true only if both true.
C) p∨q → not always true; depends on values of p,q.

             

৯৩.
Power set of empty or Null set has exactly ______ subsets.
  1. One 
  2. Two
  3. Zero
  4. Three
ব্যাখ্যা

Answer: A) One

Empty set (∅): A set that contains no elements.

Example: ∅ = {}

Power set (P(S)): The set of all subsets of a set S.

If a set has n elements,
then the power set has 2n subsets.

In empty Set, n=0 elements.

Formula: Number of subsets =2n =20=1
So, the power set of ∅ = { ∅ }

৯৪.
The order of a recurrence relation is:
  1. The largest number in the sequence
  2. The number of previous terms used to define the next term
  3.  Number of solutions
  4.  Number of sequences generated
ব্যাখ্যা

 Answer: B)
Explanation:
•    Order = number of past terms on which current term depends.
•    Example: F(n) = F(n-1) + F(n-2) → order = 2.

৯৫.
If  f:R→R,  f(x)=sinx, what is the range?
  1. [−1,1]
  2. [0,1]
  3. [0,∞)
  4.  All real numbers
ব্যাখ্যা

 Answer: A) [−1,1]

Explanation:

if x∈R , for any value of x Sine function  f(x)=sinx oscillates between -1 and 1.

Hence the range is [-1,1].

৯৬.
Pivoting in Gaussian elimination is used to:
  1. Increase computational speed
  2.  Reduce round-off errors
  3. Change order of solutions
  4.  Reduce the number of equations
ব্যাখ্যা

Answer: B

Explanation:
Partial pivoting rearranges rows so the pivot (diagonal element) has the largest magnitude. This minimizes numerical instability and round-off error.

৯৭.
The Simpson’s 1/3 Rule approximates the curve using:
  1. Straight lines
  2. Parabolas
  3.  Cubic splines
  4. Circles
ব্যাখ্যা

Answer: B) Parabolas

Explanation:
Simpson’s 1/3 rule fits a second-degree polynomial (parabola) through each pair of subintervals.


A) Straight lines
 used in Trapezoidal Rule where the function between two points is approximated by a straight line.

C) Cubic polynomial
Used in Simpson’s 3/8 Rule, which fits a cubic polynomial through four points.

D) Circle
A circle has no relation to numerical integration approximation methods.

৯৮.
Differential equations is solved by using :
  1.  Euler’s Method
  2.  Runge–Kutta Method
  3. Both A & B
  4. None
ব্যাখ্যা

Answer: C) Both A & B

Differential equations can be solved using both

1. Euler’s Method, and
2. Runge–Kutta Method.



৯৯.
The Gauss–Jordan method ends when the matrix becomes:
  1. Upper triangular
  2. Lower triangular 
  3.  Identity matrix 
  4.  Zero matrix
ব্যাখ্যা

Answer: C) Identity matrix

১০০.
For two data points, both Lagrange’s and Newton’s interpolation reduce to:
  1. Quadratic interpolation 
  2. Linear interpolation 
  3. Cubic interpolation
  4. None
ব্যাখ্যা

Answer: B) Linear interpolation 

১০১.
The process of evaluating a definite integral from a set of tabulated values of the integrand f(x) is —
  1. Numerical value
  2.  Numerical differentiation
  3. Numerical integration 
  4. Quadrature
ব্যাখ্যা

Answer: C) Numerical integration

Explanation:

Key Points:

Numerical differentiation → finds the derivative from tabulated values.

Numerical integration estimates the area under the curve using the tabulated values.

Quadrature → is another term for numerical integration.

Numerical value → just a number, not a method.

১০২.
Which type of knowledge represents “knowing how to perform a task”?
  1. Declarative knowledge
  2. Procedural knowledge  
  3. Heuristic knowledge
  4. Semantic knowledge
ব্যাখ্যা

Answer: B) Procedural knowledge

Explanation:

Knowledge can be categorized in several ways:

1. Declarative knowledge – “knowing what” Facts, concepts, rules
                                           Example: “Paris is the capital of France.”

2. Procedural knowledge – “knowing how” Knowledge of how to perform tasks or procedures
                                          Example: “How to ride a bicycle” or “How to solve a linear equation.”

3. Heuristic knowledge – “rules of thumb” Strategies or shortcuts for problem solving
                                           Example: “Try the simplest approach first.”

4. Semantic knowledge – General understanding of concepts and meanings
                                           Example: Understanding the meaning of “gravity” in physics.

Procedural knowledge is action-oriented — it’s applied knowledge for performing tasks, NOT just knowing facts.

১০৩.
Which of the following is the biggest challenge in knowledge representation?
  1. Handling uncertainty and incomplete information 
  2. Memory storage only
  3. Writing programs in PROLOG
  4. Representing binary numbers
ব্যাখ্যা

Answer: A) Handling uncertainty and incomplete information
Explanation:

        Real-world knowledge is often incomplete, ambiguous, or uncertain.

       Techniques like fuzzy logic, probabilistic reasoning, Bayesian networks help deal with uncertainty.

১০৪.
Uncertainty in expert systems can be handled by:
  1. Boolean logic
  2.  Fuzzy logic or probability 
  3.  Assembly language
  4. Graphical interface
ব্যাখ্যা

Answer: B) Fuzzy logic or probability

Explanation:

Expert systems often need to reason with incomplete, ambiguous, or uncertain information, because real-world situations rarely provide perfect or exact data. Expert systems use fuzzy logic or probabilistic methods to reason under uncertainty.

How uncertainty is handled:

Fuzzy Logic:
Deals with degrees of truth rather than just true/false.
Example: “The patient is somewhat feverish” → truth value between 0 and 1.

Probability / Certainty Factors:
Assigns a confidence level to each rule or fact.
Example: “There is an 80% chance of bacterial infection.”

Other options:

Boolean logic → only true/false, cannot model uncertainty.

Assembly language → programming language, unrelated to reasoning.

Graphical interface → only for user interaction, does not handle uncertainty.

Answer: b) Fuzzy logic or probability

১০৫.
Google Maps recommending the fastest route to avoid traffic is an example of:
  1. Random agent
  2. Model-based agent
  3.  Utility-based agent 
  4. Simple reflex agent
ব্যাখ্যা

Answer: C) Utility-based agent

Explanation:

In Artificial Intelligence (AI), agents are classified based on how they make decisions:
1. Random Agent
Takes actions randomly without reasoning

2. Model-based Agent
Maintains an internal model of the world to make decisions
Does not necessarily evaluate multiple outcomes quantitatively

3. Utility-based Agent
Chooses actions to maximize a given utility function
Can evaluate trade-offs between different choices
Example: Google Maps evaluates time, distance, traffic conditions and recommends the fastest route

4. Simple Reflex Agent
Acts only based on current percept
No consideration of future consequences or environment model
Example: Automatic light sensor

Google Maps considers multiple factors (traffic, distance, speed limits) and selects the route that maximizes utility (shortest travel time). This is the hallmark of a utility-based agent.

১০৬.
Which inference method is commonly used in First- Order-Logic (FOL) for automated reasoning?
  1.  Forward chaining 
  2.  Backward chaining 
  3. Resolution
  4. All of the above
ব্যাখ্যা

Answer: D) All of the above
Explanation:

FOL reasoning uses:

Forward chaining: Data-driven reasoning (facts → conclusion)

Backward chaining: Goal-driven reasoning (goal → required facts)

Resolution: Proof by refutation using clauses

১০৭.
ChatGPT generating coherent responses in a conversation is an example of:
  1. Natural language generation (NLG)
  2. Text summarization 
  3. Machine translation
  4.  Named entity recognition
ব্যাখ্যা

Answer: A) Natural language generation (NLG)
Explanation:
    NLG = generating human-like text from internal representations or prompts.
•   Used in chatbots, report generation, dialogue systems.

১০৮.
Autonomous cars use which AI technique to detect pedestrians and traffic signs?
  1.  Expert systems
  2. Computer vision
  3.  Forward chaining only
  4.  Bayesian networks
ব্যাখ্যা

Answer: B) Computer vision
Explanation:
    Cameras + sensors capture images → AI models recognize objects, lanes, signals, and pedestrians.

১০৯.
An AI system that predicts loan approval based on applicant data is an example of:
  1. Expert system 
  2.  Computer vision
  3. Speech recognition
  4. Depth estimation
ব্যাখ্যা

Answer: A) Expert system
Explanation:
    Uses rules and knowledge base: IF income > threshold AND credit score > threshold → approve loan.
Decision-making is rule-based, like expert systems