Electronic Engineering MCQ Question Papers: ENTC, IT Interview Placement

Subject: Digital Electronics 2

**Part 2: List for questions and answers of Digital Electronics**

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**Q1. The NAND gate output will be low if the two inputs are**

**a) 00**

**b) 01**

**c) 10**

**d) 11**

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**Q2. The number of control lines for a 8 – to – 1 multiplexer is**

**a) 2**

**b) 3**

**c) 10**

**d) 5**

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**Q3. The Gray code for decimal number 6 is equivalent to**

**a) 1100**

**b) 1001**

**c) 0101**

**d) 0101**

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**Q4. The gates required to build a half adder are**

**a) The gates required to build a half adder are**

**b) EX-OR gate and OR gate**

**c) EX-OR gate and OR gate**

**d) Four NAND gates**

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**Q5. The code where all successive numbers differ from their preceding number by single bit**

**is**

**a) Binary code**

**b) BCD**

**c) Excess – 3**

**d) Excess – 3**

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**Q6. Karnaugh map is used for the purpose of**

**a) Reducing the electronic circuits used**

**b) To map the given Boolean logic function**

**c) To minimize the terms in a Boolean expression**

**d) To maximize the terms of a given a Boolean expression **

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**Q7. A full adder logic circuit will have**

**a) Two inputs and one output**

**b) Three inputs and three outputs**

**c) Two inputs and two outputs**

**d) Three inputs and two outputs**

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**Q8. In _____ circuit does not need memory.**

**a) Combinational**

**b) Sequential**

**c) parallel**

**d) None of these**

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**Q9. Which of the following are examples of combinational circuit?**

**a) Adder**

**b) Comparator**

**c) Both (A) and (B)**

**d) None of these**

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**Q10. If Y=AC+BC is given expression then A,B and C are called as_____**

**a) Minterm**

**b) Maxterms**

**c) Literal**

**d) All of above**

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**Q11. Quad eliminates _____variables**

**a) Two**

**b) Four**

**c) Three**

**d) Five**

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**Q12. _____ eliminates three variables**

**a) Quad**

**b) Octet**

**c) Pair**

**d) None of these**

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**Q13. Don’t care condition (X) may be assumed to be _____.**

**a) 0**

**b) 1**

**c) 0 or 1**

**d) None of these **

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**Q14. IC 74LS153 is a ______**

**a) 4:1 mux**

**b) 8:1 mux**

**c) 8:1 mux**

**d) Dual 4:1 mux**

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**Q15. ……… Are used for converting one type of number system in to the other form**

**a) Decoder**

**b) logic gate**

**c) half adder**

**d) Full adder**

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**Q16. A 4:1 Demux has _________ input and __________ outputs**

**a) 1,4**

**b) 4,1**

**c) 2,4**

**d) 4,2**

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**Q17. A circuit that can convert one of ten numerical keys pressed on a keyboard to BCD is a**

**________.**

**a) Priority encoder**

**b) Decoder**

**c) Multiplexer**

**d) Demultiplexer**

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**Q18. How many 3-line-to-8-line decoders are required for a 1-of-32 decoder?**

**a) 1**

**b) 2**

**c) 4**

**d) 8**

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**Q19. How many data select lines are required for selecting eight inputs?**

**a) 1**

**b) 2**

**c) 3**

**d) 4 **

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**Q20. How many 1-of-16 decoders are required for decoding a 7-bit binary number?**

**a) 5**

**b) 6**

**c) 7**

**d) 8 **

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**Part 2: List for questions and answers of Digital Electronics**

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**Q1. Answer: d**

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**Q2. Answer: b**

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**Q3. Answer: c**

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**Q4. Answer: c**

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**Q5. Answer: d**

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**Q6. Answer: c**

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**Q7. Answer: d**

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**Q8. Answer: a**

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**Q9. Answer: c**

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**Q10. Answer: c**

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**Q11. Answer: a**

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**Q12. Answer: b**

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**Q13. Answer: c**

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**Q14. Answer: d**

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**Q15. Answer: a**

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**Q16. Answer: b**

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**Q17. Answer: a**

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**Q18. Answer: c**

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**Q19. Answer: c**

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**Q20. Answer: d**