Digital Electronics MCQs

Multiple Choice Questions 25 Pages

Mahatma Gandhi University

BSc Computer Science

MPC

Contributed by

Manpreet Prasad Chaudhuri

Complementry II DIGITAL ELECTRONICS
For BSc Computer Science Off Campus Stream

1. The number of levels in a digital signal is
1. One
2. Two
3. Four
4. Ten

2. In any flip-flop, when the Q output is 1, what is the state if the Q terminal?
1. 0
2. 1
3. Either 1 or 0

3. The slow turning of a potentiometer is
1. Digital input
2. Analog output
3. Nature of output depends on voltage
4. It depends on resolution of the potentiometer

4. Which of the following can provide a digital signal?
1. Slow change in the value of a resistor
2. Sine wave
3. Square wave
4. Gradual turning of a potentiometer
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5. The high voltage level of a digital signal in positive logic is
1. 1
2. 0
3. Either 1 or 0

6. A device that converts from decimal to binary numbered is called
1. Decoder
2, Encoder
3. CPU
4. Converter

7. Decimal 15 in binary system can b e written as
1. 1111
2. 1110
3. 1100
4. 1000

8. If 4 in binary system is 100 then 8 will be
1. 10
2. 100
3. 111
4. 1000

9. Binary 1010 in decimal system is equivalent to
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1. 13
2. 19
3. 10
4. 23

10. Binary 1111 when subtracted from binary 11111, the result in binary is
1. 111111
2. 1111
3. 1000
4. 10000

11. Binary 1111 when added to binary 11111 is
1. 101110
2. 10110
3. 10000
4. 100010

12. Binary 1000 multiplied by binary 1000 gives
1. 10000
2. 100000
3. 1000000
4. 10000000

13. Which of the following is not valid in binary system?
1. 0x0=0
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2. 0x1=1
3. 1x1=1
4. All of the above

14. Which of the following represents the decimal form of binary 0.0111?
1. 0.1600
2. 0.2728
3. 0.4375
4. 0.7964

15. Which of the following is decimal equivalent of the binary 1111111?
1. 67
2. 87
3. 127
4. 167

16. The decimal equivalent of the binary number 10110.0101011101
1. 22.3408216500
2. 22.3408216750
3. 22.3408213125
4. 22.3408203125

17. Which binary addition is incorrect?
1. 1001.1 + 1011.01 = 10100.11
2. 1000101 + 1000101 = 1001010
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3. 0.1011 + 0.1101 = 1.1
4. 1011.01 + 1001.11 = 10111

18. Which binary addition is incorrect?
1. 1101.1 + 1011.1 = 11001.0
2. 101101 + 1101101 = 1100011
3. 010011 + 0.1110 = 1.0001
4. 1100.011 + 1011.011 = 10111.100

19. Which binary subtraction is incorrect?
1. 100101 – 100011 = 000000
2. 10000000 - 01000000 = 1000000
3. 10111110.1 – 101011.11 = 110010.11
4. 11111111 – 1111111 = 10000000

20. Which of the following binary product is incorrect?
1. 1100 x 1010 = 1111000
2. 1.01 x10.1 = 11.001
3. 1100110 x 1000 = 1100110000
4. None of the above

21. Binary 1000 will be the result of which of the following
1. Binary 1000 – 100
2. Binary 1011 – 1111
3. Binary 1111 – 111
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4. Binary 11111 – 1111

22. Which of the binary addition is incorrect?
1. 1001 + 1101 = 10110
2. 10101 + 10011 = 101000
3. 11111 + 11111 = 100000
4. 11111 + 10001 + 110000

23. Binary 101010 is equivalent to decimal number
1. 24
2. 42
3. 44
4. 64

24. Decimal number 5436 when converted into 9's complement will become
1. 4356
2. 4653
3. 4563
4. 4655

25. Decimal 1932 when converted into 10's complement will become
1. 8868
2. 8068
3. 8608
4. 8806
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26. Octal 16 is equal to decimal
1. 13
2. 14
3. 15
4. 16

27. According to Boolean algebra, 1+ A+B+C is equal to
1. A+B+C
2. ABC
3. 1+ABC
4. 1

28. Which logic gate is similar to the function of two series switches?
1. AND
2. OR
3. NAND
4. All of the above

29. Which logic gate is similar to the function of two parallel switches?
1. AND
2. NAND
3. OR
4. NOR

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30. Which logic function has the output law only when both inputs are high?
1. OR
2. NOR
3. AND
4. NAND

31. The decimal equivalent of the hexadecimal number E5 is
1. 279
2. 229
3. 327
4. 227

32. The radix of a hexadecimal system is
1. 2
2. 3
3. 8
4. 16

33. Which of the following register pairs can be directly stored in memory
1. BC
2. DE
3. HL
4. EF

34. The delay between successive bits for 9600 band rate is approximately 0.1 ms
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1. True
2. False
3. Maybe
4. None of the above

35. How many inputs can be supplied to a logic gate with a fan in factor of four?
1. Two
2. Three
3. Four
4. Eight

36. Which circuit is used for a clock generator?
1. A free running MV
2. JK flip-flop
3. Either of A and B
4. Neither of A and B

37. How many flip-flop circuits are needed to divide by 16?
1. Two
2. Four
3. Eight
4. Sixteen

38. An index register in a digital computer is used for
1. Address modification
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2. For indirect address
3. Storing one of the operands
4. Pointing to the stack address

39. An index register in digital computer is register to be used for
1. Performing arithmetic and logic operations
2. Temporary storage of result
3. Counting number of times a program is executed
4. Address modification purpose

40. A toggle operation is used
1. Without a flip-flop
2. With a flip-flop
3. With a gate circuit
4. With a flip-flop and a gate circuit

41. How many flip-flops are needed for a 4 bit counter?
1. Two
2. Three
3. Four
4. Six

42. Which of the following is used as a data selector?
1. Encoder
2. Decoder
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Digital Electronics MCQs

Digital Electronics MCQs

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