MCQOPTIONS
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MCQOPTIONS
This section includes 657 Mcqs, each offering curated multiple-choice questions to sharpen your Testing Subject knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
A buffer is a device that isolates other devices. Typically a buffer has |
| A. | a high input impedance and a low output impedance |
| B. | a high input impedance as well as output impedance |
| C. | a low input impedance and a high output impedance |
| D. | a low input impedance as well as output impedance |
| Answer» B. a high input impedance as well as output impedance | |
| 2. |
In a positive edge triggered D flip flop |
| A. | D input is called direct set |
| B. | Preset is called direct reset |
| C. | Present and clear are called direct set and reset respectively |
| D. | D input overrides other inputs |
| Answer» D. D input overrides other inputs | |
| 3. |
Which of the following is used as switch? |
| A. | J-K flip-flop |
| B. | Master slave J-K flip-flop |
| C. | T-flip-flop |
| D. | D-flip-flop |
| Answer» E. | |
| 4. |
The first contribution to logic was made by |
| A. | George Boole |
| B. | Copernicus |
| C. | Aristotle |
| D. | Shannon |
| Answer» D. Shannon | |
| 5. |
Average latency time of magnetic tape memory is of the order of |
| A. | 1 sec |
| B. | 1 msec |
| C. | 1 sec |
| D. | 1 minute |
| Answer» E. | |
| 6. |
The output impedance of a logic pulser is |
| A. | low |
| B. | high |
| C. | may be Low or High |
| D. | can't say |
| Answer» B. high | |
| 7. |
In a J-K flip flop the input J = K = 1 pulse is about |
| A. | set |
| B. | reset |
| C. | no change |
| D. | toggle |
| Answer» E. | |
| 8. |
The communicating capacitor reduces turn on time because |
| A. | it acts as an open circuit |
| B. | it allows maximum base circuit to flow |
| C. | it aids in removing the excess carrier from the base region |
| D. | none of these |
| Answer» C. it aids in removing the excess carrier from the base region | |
| 9. |
With a JK master-slave flip-flop the master is clocked when the clock is __________ , and the slave is triggered when the clock is __________ . |
| A. | low, low |
| B. | high, low |
| C. | low, high |
| D. | high, high |
| Answer» C. low, high | |
| 10. |
Four MSI TTL 4-bit ripple counters are cascaded to form a 16-bit binary counter. Its propagation delay is about __________ nanoseconds. |
| A. | 70 |
| B. | 140 |
| C. | 210 |
| D. | 280 |
| Answer» E. | |
| 11. |
The accuracy of A/D conversion is generally |
| A. | <img src="/_files/images/electronics-and-communication-engineering/digital-electronics/19-199-1.png"> |
| B. | LSB |
| C. | <img src="/_files/images/electronics-and-communication-engineering/digital-electronics/19-199-3.png"> |
| D. | none of the above |
| Answer» B. LSB | |
| 12. |
To convert JK flip flop to D flip flop |
| A. | connect D to both J and K |
| B. | connect D to J directly and D to K through inverter |
| C. | connect D to K directly and D to J through inverter |
| D. | connect D to K and leave J open |
| Answer» C. connect D to K directly and D to J through inverter | |
| 13. |
Read cycle is always followed by (during instructions execution) |
| A. | read cycle |
| B. | write cycle |
| C. | delete signal |
| D. | none of these |
| Answer» C. delete signal | |
| 14. |
Semiconductor ROM's are sometimes preferred to semiconductor RAM's because |
| A. | ROM's are cheaper than RAMs |
| B. | ROMs are faster |
| C. | ROMs do not require power supply for their operations |
| D. | Programs stored in ROMs cannot be altered either by the power failure or by the user |
| Answer» E. | |
| 15. |
RAMs can be built with bipolar or CMOS transistor RAMs that are not possible with bipolar transistors are |
| A. | SRAM |
| B. | SRAM, DRAM |
| C. | DRAM |
| D. | PROM |
| Answer» D. PROM | |
| 16. |
In D-type FF, Preset (Pr) and clear (Clr) inputs are called |
| A. | Synchronous |
| B. | Asynchronous |
| C. | Data |
| D. | None |
| Answer» C. Data | |
| 17. |
RS latch can be built with |
| A. | NOR gates |
| B. | NAND gates |
| C. | NOR or NAND gates |
| D. | none of the above |
| Answer» D. none of the above | |
| 18. |
Which memory is available in all technologies? |
| A. | PROM |
| B. | EEPROM |
| C. | ROM |
| D. | EPROM |
| Answer» B. EEPROM | |
| 19. |
Decimal number 5436 when converted into 9's complement will become |
| A. | 4356 |
| B. | 4653 |
| C. | 4563 |
| D. | 4655 |
| Answer» D. 4655 | |
| 20. |
What is output 'Z' of an EX-OR gate, whose all inputs are set at A? |
| A. | Z = A |
| B. | Z = 1 |
| C. | Z = 0 |
| D. | Z = A |
| Answer» D. Z = A | |
| 21. |
Minimum number of J-K flip-flop needed to construct a BCD counter is |
| A. | 2 |
| B. | 3 |
| C. | 4 |
| D. | 5 |
| Answer» D. 5 | |
| 22. |
The following switching functions are to be implemented using a decoder f1 = m (1, 2, 4, 8, 10, 14)f2 = m (2, 5, 9, 15)f3 = m (2, 4, 5, 6, 7) The minimum configuration of decoder is |
| A. | 2 to 4 line |
| B. | 3 to 8 line |
| C. | 4 to 16 line |
| D. | 5 to 32 line |
| Answer» D. 5 to 32 line | |
| 23. |
For the logic circuit of the given figure the simplified Boolean expression is |
| A. | A B |
| B. | A + B |
| C. | AB |
| D. | <span style="text-decoration:overline;">A</span> |
| E. | + B |
| Answer» B. A + B | |
| 24. |
In 8085, to disable the whole interrupt system (except TRAP) |
| A. | the DI instruction may be used |
| B. | the DO instruction may be used |
| C. | the INTERRUPT instruction may be used |
| D. | the El instruction may be used |
| Answer» B. the DO instruction may be used | |
| 25. |
The reason for glitches on the outputs of decoding gates on a synchronous counter is |
| A. | FFs changing states together |
| B. | FFs changing states one at a time |
| C. | AND gates not functioning properly |
| D. | none of the above |
| Answer» C. AND gates not functioning properly | |
| 26. |
EEPROM is also known as |
| A. | UVPROM |
| B. | EAPROM |
| C. | both UVPROM and EAPROM |
| D. | none of the above |
| Answer» C. both UVPROM and EAPROM | |
| 27. |
The MOS symbols shown indicates: that it is depletion typethat it is enhancement typethat it is n channelthat it is p channelthat electrons flow from D to Sthat holes flow from D to S The only true statements are |
| A. | 1, 3, 6 |
| B. | 2, 4, 6 |
| C. | 1, 3, 5 |
| D. | 2, 3, 6 |
| Answer» B. 2, 4, 6 | |
| 28. |
TTL circuit with active pull up is preferred because of its suitability for |
| A. | wired AND operation |
| B. | bus operated system |
| C. | wired logic operation |
| D. | reasonable dissipation and speed of operation |
| Answer» E. | |
| 29. |
A parity check usually can detect |
| A. | one-bit error |
| B. | double-bit error |
| C. | three-bit error |
| D. | any-bit error |
| Answer» B. double-bit error | |
| 30. |
Which of the following is 'synchronous'? |
| A. | Half adder |
| B. | Full adder |
| C. | R-S flip-flop |
| D. | Clocked R-S flip-flop |
| Answer» E. | |
| 31. |
TRAP is __________ whereas RST 7.5, RST 6.5, RST 5.5 are __________ . |
| A. | maskable, non-maskable |
| B. | maskable, maskable |
| C. | non-maskable, non-maskable |
| D. | non-maskable, maskable |
| Answer» E. | |
| 32. |
In a flip-flop with a NAND latch, a low R and a low S produces |
| A. | active condition |
| B. | inactive condition |
| C. | race condition |
| D. | dead condition |
| Answer» D. dead condition | |
| 33. |
If a microcomputer has a 64 K memory; what is the hexadecimal notations for the first memory location? |
| A. | AAAA |
| B. | FFFF |
| C. | AAA0 |
| D. | 0000 |
| Answer» E. | |
| 34. |
In figure, R = 20K and C = 75 pF. The converter clock frequency will be |
| A. | 606 Hz |
| B. | 1212 Hz |
| C. | 555 KHz |
| D. | 606 KHz |
| Answer» B. 1212 Hz | |
| 35. |
ECL can be used to high frequencies in the order of |
| A. | 500 kHz |
| B. | 1 MHz |
| C. | 100 MHz |
| D. | 500 MHz |
| Answer» E. | |
| 36. |
In the switching circuit, switches A, B have value 0 for OFF, 1 for ON and the output Y has 0 volts for 1 volts, then the expression for Y is |
| A. | AB |
| B. | A + B |
| C. | <span style="text-decoration:overline;">A + B</span> |
| D. | AB |
| Answer» D. AB | |
| 37. |
2's complement number 00011111 = __________ 10 |
| A. | +31 |
| B. | -31 |
| C. | +11 |
| D. | -11 |
| Answer» B. -31 | |
| 38. |
In 8085 microprocessor, what is the length of temporary register? |
| A. | 6 bits |
| B. | 8 bits |
| C. | 12 bits |
| D. | 16 bits |
| Answer» C. 12 bits | |
| 39. |
In a positive edge triggered JK flip flop, J = 1, K = 0 and clock pulse is rising Q will |
| A. | be 0 |
| B. | be 1 |
| C. | show no change |
| D. | toggle |
| Answer» C. show no change | |
| 40. |
What is the gray code word for EX-OR the binary number 101011? |
| A. | 101011 |
| B. | 110101 |
| C. | 111110 |
| D. | 011111 |
| Answer» E. | |
| 41. |
Digital circuits mostly use |
| A. | Diodes |
| B. | Bipolar transistors |
| C. | Diodes and bipolar transistors |
| D. | Bipolar transistors and FETs |
| Answer» D. Bipolar transistors and FETs | |
| 42. |
The contents of stack location after the call operation will be |
| A. | 00000111 |
| B. | 00001110 |
| C. | 00001010 |
| D. | 00001111 |
| Answer» B. 00001110 | |
| 43. |
A 16 bit binary adder has |
| A. | 16 half adders |
| B. | 16 full adders |
| C. | one half adders and 15 full adders |
| D. | 8 half adders and eight full adders |
| Answer» D. 8 half adders and eight full adders | |
| 44. |
The hexadecimal number 5 F is equal to binary number |
| A. | 1010011 |
| B. | 1011001 |
| C. | 1010101 |
| D. | 1011111 |
| Answer» E. | |
| 45. |
Which of the following methods is used for solving differential equations numerically? |
| A. | Runge-Kutta method |
| B. | Gauss-elimination method |
| C. | Newton-Raphson method |
| D. | Any one of these |
| Answer» B. Gauss-elimination method | |
| 46. |
Some ADCs are ParallelUpdownSingle slopeDual slopeSuccessive approximationStair step Out of above which ones do not use DAC? |
| A. | 1 only |
| B. | 1, 3, 4 |
| C. | 1, 2, 3 |
| D. | 1, 5, 6 |
| Answer» C. 1, 2, 3 | |
| 47. |
As compared to TTL, ECL has |
| A. | lower power dissipation |
| B. | lower propagation delay |
| C. | higher propagation delay |
| D. | higher noise margin |
| Answer» C. higher propagation delay | |
| 48. |
The problem of current lagging is associated with |
| A. | DCTL gates |
| B. | DTL gates |
| C. | ECL gates |
| D. | CMOS gates |
| Answer» B. DTL gates | |
| 49. |
Binary 1111 when subtracted from binary 11111 is |
| A. | 101110 |
| B. | 10110 |
| C. | 10000 |
| D. | 100010 |
| Answer» B. 10110 | |
| 50. |
In a NOT gate the output is always the opposite of the input. |
| A. | True |
| B. | False |
| Answer» B. False | |