MCQOPTIONS
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MCQOPTIONS
This section includes 106 Mcqs, each offering curated multiple-choice questions to sharpen your Digital Electronics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
If the output of an enable circuit must be HIGH when the circuit is disabled, should an AND gate or an OR gate be used for the circuit? |
| A. | AND gate |
| B. | OR gate |
| C. | Either gate can be used. |
| D. | Neither gate can be used. |
| Answer» C. Either gate can be used. | |
| 2. |
Which of the following equations would accurately describe a four-input OR gate when = 1, = 1, = 0, and = 0? |
| A. | 1 + 1 + 0 + 0 = 01 |
| B. | 1 + 1 + 0 + 0 = 1 |
| C. | 1 + 1 + 0 + 0 = 0 |
| D. | 1 + 1 + 0 + 0 = 00 |
| Answer» C. 1 + 1 + 0 + 0 = 0 | |
| 3. |
Which of the following gates is described by the expression ? |
| A. | OR |
| B. | AND |
| C. | NOR |
| D. | NAND |
| Answer» E. | |
| 4. |
Write the Boolean expression for an inverter logic gate with input and output . |
| A. | = |
| B. | = |
| Answer» C. | |
| 5. |
The power dissipation, P, of a logic gate is the product of the ________. |
| A. | dc supply voltage and the peak current |
| B. | dc supply voltage and the average supply current |
| C. | ac supply voltage and the peak current |
| D. | ac supply voltage and the average supply current |
| Answer» C. ac supply voltage and the peak current | |
| 6. |
The logic expression for a NOR gate is ________. |
| A. | [A]. |
| B. | [B]. |
| C. | [C]. |
| D. | [D]. |
| Answer» E. | |
| 7. |
The expression of an EXOR gate is ____________ |
| A. | A’B+AB’ |
| B. | AB+A’B’ |
| C. | A+A.B |
| D. | A’+B’ |
| Answer» B. AB+A’B’ | |
| 8. |
The gate which is called an inverter is called _________ |
| A. | NOR |
| B. | NAND |
| C. | EXOR |
| D. | NOT |
| Answer» E. | |
| 9. |
The universal gate that can be used to implement any Boolean expression is __________ |
| A. | NAND |
| B. | EXOR |
| C. | OR |
| D. | AND |
| Answer» B. EXOR | |
| 10. |
When logic gates are connected to form a gating/logic network it is called as a ______________ logic circuit. |
| A. | combinational |
| B. | sequential |
| C. | systematic |
| D. | hardwired |
| Answer» B. sequential | |
| 11. |
Which of the following gate will give a 0 when both of its inputs are 1? |
| A. | AND |
| B. | OR |
| C. | NAND |
| D. | EXOR |
| Answer» D. EXOR | |
| 12. |
The gate which is used to reverse the output obtained is _____ |
| A. | NOR |
| B. | NAND |
| C. | EXOR |
| D. | NOT |
| Answer» E. | |
| 13. |
The boolean expression of an OR gate is _______ |
| A. | A.B |
| B. | A’B+AB’ |
| C. | A+B |
| D. | A’B’ |
| Answer» D. A’B’ | |
| 14. |
A __________ gate gives the output as 1 only if all the inputs signals are 1. |
| A. | AND |
| B. | OR |
| C. | EXOR |
| D. | NOR |
| Answer» B. OR | |
| 15. |
Logic Gates are the building blocks of all circuits in a computer. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 16. |
Electronic circuits that operate on one or more input signals to produce standard output _______ |
| A. | Series circuits |
| B. | Parallel Circuits |
| C. | Logic Signals |
| D. | Logic Gates |
| Answer» E. | |
| 17. |
An AND gate output is LOW if all the inputs are HIGH. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 18. |
Power is connected to pins 7 and 14 of a 7408 quad two-input AND gate IC to allow voltage for all four AND gates on the IC. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 19. |
An OR array is programmed by blowing fuses to eliminate selected variables from the output functions. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 20. |
When does the output of a NAND gate = 1? |
| A. | Whenever a 0 is present at an input |
| B. | Only when all inputs = 0 |
| C. | Whenever a 1 is present at an input |
| D. | Only when all inputs = 1 |
| Answer» B. Only when all inputs = 0 | |
| 21. |
An inverter output is the complement of its input. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 22. |
A waveform can be enabled or disabled by both AND and OR gates. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 23. |
When does the output of a NOR gate = 0? |
| A. | Whenever a 0 is present at an input |
| B. | Only when all inputs = 0 |
| C. | Whenever a 1 is present at an input |
| D. | Only when all inputs = 1 |
| Answer» D. Only when all inputs = 1 | |
| 24. |
A NAND gate output is LOW only if all the inputs are HIGH. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 25. |
A logic pulser is used to determine the level of floating in a circuit. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 26. |
An exclusive-OR gate output is HIGH when the inputs are unequal. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 27. |
The number of input combinations for a 4-input gate is ________. |
| A. | 9 |
| B. | 8 |
| C. | 15 |
| D. | 16 |
| Answer» E. | |
| 28. |
In a Boolean equation the use of the + symbol represents the OR function. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 29. |
An OR gate output is HIGH only if all the inputs are HIGH. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 30. |
It is important to memorize logic symbols, Boolean equations, and truth tables for logic gates. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 31. |
The gates in this figure are implemented using TTL logic. If the output of the inverter has an internal open circuit, what voltage would you expect to measure at the inverter's output? |
| A. | Less than 0.4 V |
| B. | 1.6 V |
| C. | Greater than 2.4 V |
| D. | All of the above |
| Answer» C. Greater than 2.4 V | |
| 32. |
The output of an XOR gate is HIGH only when ________. |
| A. | both inputs = 0 |
| B. | both inputs = 1 |
| C. | the two inputs are unequal |
| D. | both inputs are undefined |
| Answer» D. both inputs are undefined | |
| 33. |
The output of an exclusive-NOR gate is HIGH if ________. |
| A. | the inputs are equal |
| B. | one input is HIGH, and the other input is LOW |
| C. | the inputs are unequal |
| D. | none of the above |
| Answer» B. one input is HIGH, and the other input is LOW | |
| 34. |
Which of the following choices meets the minimum requirement needed to create specialized waveforms that are used in digital control and sequencing circuits? |
| A. | basic gates, a clock oscillator, and a repetitive waveform generator |
| B. | basic gates, a clock oscillator, and a Johnson shift counter |
| C. | basic gates, a clock oscillator, and a DeMorgan pulse generator |
| D. | basic gates, a clock oscillator, a repetitive waveform generator, and a Johnson shift counter |
| Answer» B. basic gates, a clock oscillator, and a Johnson shift counter | |
| 35. |
Write the Boolean expression for an inverter logic gate with input C and output Y. |
| A. | Y = C |
| B. | Y = |
| Answer» C. | |
| 36. |
Output will be a LOW for any case when one or more inputs are zero for a(n): |
| A. | OR gate |
| B. | NOT gate |
| C. | AND gate |
| D. | NOR gate |
| Answer» D. NOR gate | |
| 37. |
A popular waveform generator is the Johnson shift counter. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 38. |
If A is LOW or B is LOW or BOTH are LOW, then X is LOW. If A is HIGH and B is HIGH, then X is HIGH. These rules specify the operation of a(n) ________. |
| A. | AND gate |
| B. | OR gate |
| C. | NAND gate |
| D. | XOR gate |
| Answer» B. OR gate | |
| 39. |
How many pins does the 4049 IC have? |
| A. | 14 |
| B. | 16 |
| C. | 18 |
| D. | 20 |
| Answer» C. 18 | |
| 40. |
How many input combinations would a truth table have for a six-input AND gate? |
| A. | 32 |
| B. | 48 |
| C. | 64 |
| D. | 128 |
| Answer» D. 128 | |
| 41. |
A major advantage of ECL logic over TTL and CMOS is ________. |
| A. | low power dissipation |
| B. | high speed |
| C. | both low power dissipation and high speed |
| D. | neither low power dissipation nor high speed |
| Answer» C. both low power dissipation and high speed | |
| 42. |
The output of a NOR gate is HIGH if ________. |
| A. | all inputs are HIGH |
| B. | any input is HIGH |
| C. | any input is LOW |
| D. | all inputs are LOW |
| Answer» E. | |
| 43. |
Which of the following logical operations is represented by the + sign in Boolean algebra? |
| A. | inversion |
| B. | AND |
| C. | OR |
| D. | complementation |
| Answer» D. complementation | |
| 44. |
If a 3-input AND gate has eight input possibilities, how many of those possibilities will result in a HIGH output? |
| A. | 1 |
| B. | 2 |
| C. | 7 |
| D. | 8 |
| Answer» B. 2 | |
| 45. |
The output of an exclusive-OR gate is HIGH if ________. |
| A. | all inputs are LOW |
| B. | all inputs are HIGH |
| C. | the inputs are unequal |
| D. | none of the above |
| Answer» D. none of the above | |
| 46. |
A logic gate has one or more output terminals and one input terminal. |
| A. | 1 |
| B. | |
| C. | 1 |
| D. | |
| Answer» C. 1 | |
| 47. |
From the truth table for a three-input NOR gate, what is the only condition of inputs A, B, and C that will make the output X high? |
| A. | A = 1, B = 1, C = 1 |
| B. | A = 1, B = 0, C = 0 |
| C. | A = 0, B = 0, C = 1 |
| D. | A = 0, B = 0, C = 0 |
| Answer» E. | |
| 48. |
The basic logic gate whose output is the complement of the input is the: |
| A. | OR gate |
| B. | AND gate |
| C. | inverter |
| D. | comparator |
| Answer» D. comparator | |
| 49. |
What is the Boolean expression for a four-input OR gate? |
| A. | Y = A + B + C + D |
| B. | Y = A· B · C · D |
| C. | Y = A – B – C – D |
| D. | Y = A $ B $ C $ D |
| Answer» B. Y = A¬∑ B ¬∑ C ¬∑ D | |
| 50. |
A 2-input gate that can be used to pass a digital waveform unchanged at certain times and inverted at other times is a(n) ________. |
| A. | AND gate |
| B. | OR gate |
| C. | NAND gate |
| D. | XOR gate |
| Answer» E. | |