Digital Electronics 1

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Electronic Engineering MCQ Question Papers: ENTC, IT Interview Placement

Subject:  Digital Electronics 1

Part 1: List for questions and answers of Digital Electronics

 

Q1. Low power dissipation is desired in large systems as it leads to

a) Lower cooling costs

b) Lower power supply and distribution costs

c) Reduction in mechanical design problems

d) All of above

 

Q2. Which of the following logic families has the shortest propagation delay?

a) CMOS

b) BiCMOS

c) ECL

d) RTL

 

Q3. Power dissipation increases linearly as a function of the

a) Frequency of switching

b) Current

c) Input voltage

d) None of above

 

Q4. The noise margin of a logic gate is a measure of its noise immunity, a gate’s ability to withstand

a) Output signal variations

b) Input signal variations

c) Power supply variations

d) None of above

 

Q5. The shorter the propagation delay

a) Higher is the speed of the circuit

b) Slower is the speed of the circuit

c) Depends on the logic family

d) None of above

 

Q6. There are ___ number of propagation delays associated with a logic gate

a) 1

b) 2

c) 4

d) 5 

 

Q7. The reference points on the wave forms with respect to which the time delays are measured can be chosen as

a) The 40% of the leading and trailing edges of the wave forms

b) The 50% of the leading and trailing edges of the wave forms

c) The 60% of the leading and trailing edges of the wave forms

d) The 100% of the leading and trailing edges of the wave forms

 

Q8. The military IC series has a universal requirement for operability from

a) -30 deg. C to 55 deg. C

b) -30 deg. C to 85 deg. C

c) 0 deg. C to 55 deg. C

d) 0 deg. C to 55 deg. C

 

Q9. The time taken for the output of a gate to change after the inputs have changed is called

a) Transient response

b) Propagation delay

c) Noise immunity

d) None of above

 

Q10. The delay conditions tPHL and tPLH are not necessarily equal and vary depending on

a) Load conditions

b) Input conditions

c) supply

d) none of above

 

Q11. __________ is the function of output impedance of the driving gate and the input impedance of driven gate

a) Fan- in

b) Fan- out

c) Propagation delay

d) None of above

 

Q12. . The difference between operation input voltage level and threshold voltage is called _____________ of the circuit

a) Noise margin

b) Noise

c) Noise voltage

d) None of above 

 

Q13. Which family of logic circuits uses field effect transistors?

a) TTL

b) 5 TTL

c) 8 TTL

d) 10 TTL

 

Q14. The maximum propagation value in case of 7400 NAND gate is

a) 1 second

b) 20 milli-seconds

c) Less than 20 nano-seconds

d) Less than 20 pico-seconds

 

Q15. Less than 20 pico-seconds

a) 5 V dc

b) 10 V dc

c) 2 V dc

d) 20 V dc

 

Q16. The voltage needed for a TTL IC power supply is

a) 5 V dc

b) 10 V dc

c) 2 V dc

d) 20 V dc

 

Q17. The digital logic family which has minimum power dissipation is

a) TTL

b) RTL

c) DTL

d) CMOS

 

Q18. In digital ICs, Schottky transistors are preferred over normal transistors because of their

a) Lower Propagation delay

b) Higher Propagation delay

c) Lower Power dissipation

d) Higher Power dissipation 

 

Q19. CMOS circuits consume power

a) Equal to TTL

b) Less than TTL

c) Twice of TTL

d) Thrice of TTL

 

Q20. In a positive logic system, logic state 1 corresponds to

a) Positive voltage

b) Higher voltage level

c) Zero voltage level

d) Zero voltage level 

 

Part 1: List for questions and answers of Digital Electronics

 

Q1. Answer: d

 

Q2. Answer: c

 

Q3. Answer: a

 

Q4. Answer: b

 

Q5. Answer: a

 

Q6. Answer: b

 

Q7. Answer: b

 

Q8. Answer: d

 

Q9. Answer: b

 

Q10. Answer: a

 

Q11. Answer: b

 

Q12. Answer: a

 

Q13. Answer: d

 

Q14. Answer: c

 

Q15. Answer: a

 

Q16. Answer: a

 

Q17. Answer: d

 

Q18. Answer: a

 

Q19. Answer: b

 

Q20. Answer: b