MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 158 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics & Communication Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The Norton current is sometimes called the |
| A. | shorted-load current |
| B. | open-load current |
| C. | thevenin current |
| D. | thevenin voltage |
| Answer» B. open-load current | |
| 2. |
Kirchhoff’s current law is applicable only to |
| A. | junction in a network |
| B. | closed loops in a network |
| C. | electric circuits |
| D. | electronic circuits |
| Answer» B. closed loops in a network | |
| 3. |
How many transistors must be used in a class B power amplifier to obtain the output for the full cycle of the signal? |
| A. | 0 |
| B. | 1 |
| C. | 2 |
| D. | 3 |
| Answer» D. 3 | |
| 4. |
Which type of amplifier uses pulse (digital) signals in its operation? |
| A. | class a |
| B. | class b or ab |
| C. | class c |
| D. | class d |
| Answer» E. | |
| 5. |
In class A operation, the operating point is generally located                of the d.c. load line. |
| A. | at cut off point |
| B. | at the middle |
| C. | at saturation point |
| D. | none of the above |
| Answer» C. at saturation point | |
| 6. |
What is the maximum efficiency of a class A circuit with a direct or series-fed load connection? |
| A. | 90% |
| B. | 78.50% |
| C. | 50% |
| D. | 25% |
| Answer» E. | |
| 7. |
The Q-point is at cutoff for class operation. |
| A. | a |
| B. | b |
| C. | c |
| D. | ab |
| Answer» C. c | |
| 8. |
Which type of power amplifier is biased for operation at less than 180º of the cycle? |
| A. | class a |
| B. | class b or ab |
| C. | class c |
| D. | class d |
| Answer» D. class d | |
| 9. |
Heat sinks reduce the |
| A. | transistor power |
| B. | ambient temperature |
| C. | junction temperature |
| D. | collector current |
| Answer» D. collector current | |
| 10. |
Class-C amplifiers are almost always |
| A. | transformer- coupled between stages |
| B. | operated at audio frequencies |
| C. | tuned rf amplifiers |
| D. | wideband |
| Answer» D. wideband | |
| 11. |
Transformer coupling is an example of |
| A. | direct coupling |
| B. | ac coupling |
| C. | dc coupling |
| D. | impedance coupling |
| Answer» C. dc coupling | |
| 12. |
For Class-B operation, the collector current flows for |
| A. | the whole cycle |
| B. | half the cycle |
| C. | less than half a cycle |
| D. | less than a quarter of a cycle |
| Answer» C. less than half a cycle | |
| 13. |
The class amplifier is biased below cutoff. |
| A. | a |
| B. | ab |
| C. | b |
| D. | c |
| Answer» D. c | |
| 14. |
The principal advantage(s) of BJTs over MOSFETs is (are) that |
| A. | voltage drop across the transistor is important. |
| B. | they are not as prone to esd. |
| C. | both of the above |
| D. | none of the above |
| Answer» D. none of the above | |
| 15. |
The principal advantage(s) of MOSFETs over BJTs is (are) |
| A. | their biasing networks are simpler. |
| B. | their drive requirements are simpler. |
| C. | they can be connected in parallel for added drive capability. |
| D. | all of the above |
| Answer» E. | |
| 16. |
Which class of amplifier operates in the linear region for only a small part of the input cycle? |
| A. | a |
| B. | b |
| C. | c |
| D. | ab |
| Answer» D. ab | |
| 17. |
A class amplifier is biased slightly above cutoff and operates in the linear region for slightly more than 180º of the input cycle. |
| A. | a |
| B. | b |
| C. | c |
| D. | ab |
| Answer» E. | |
| 18. |
The maximum efficiency of a class B amplifier is percent. |
| A. | 50 |
| B. | 25 |
| C. | 70 |
| D. | 79 |
| Answer» E. | |
| 19. |
Class amplifiers are normally operated in a push-pull configuration in order to produce an output that is a replica of the input. |
| A. | a |
| B. | b |
| C. | c |
| D. | ab |
| Answer» E. | |
| 20. |
The Q-point is at cutoff for class operation. |
| A. | a |
| B. | b |
| C. | c |
| D. | ab |
| Answer» C. c | |
| 21. |
In practice, the efficiency of a capacitively coupled class A amplifier is about %. |
| A. | 25 |
| B. | 40 |
| C. | 70 |
| D. | 10 |
| Answer» E. | |
| 22. |
A class C amplifier has a tank circuit in the output. The amplifier is conducting only 28°. The output voltage is |
| A. | 0 v. |
| B. | a dc value equal to vcc. |
| C. | a sine wave. |
| D. | a square wave with a frequency determined by the tank. |
| Answer» D. a square wave with a frequency determined by the tank. | |
| 23. |
A class A amplifier with RC = 3.3 kΩ and RE = 1.2 kΩ has a VCC = 20 V. Find IC(sat). |
| A. | 4.4 ma |
| B. | 6.1 ma |
| C. | 16.7 ma |
| D. | 20 ma |
| Answer» B. 6.1 ma | |
| 24. |
You have an application for a power amplifier to operate on FM radio frequencies. The most likely choice would be a            amplifier. |
| A. | class a |
| B. | class b |
| C. | class c |
| D. | class ab |
| Answer» D. class ab | |
| 25. |
A class A amplifier has a voltage gain of 30 and a current gain of What is the power gain? |
| A. | 30 |
| B. | 25 |
| C. | 1.2 |
| D. | 750 |
| Answer» E. | |
| 26. |
Transmit time is the time taken by the electrons on holes to pass from |
| A. | emitter to collector |
| B. | collector to emitter |
| C. | base to emitter |
| D. | base to collector |
| Answer» B. collector to emitter | |
| 27. |
Which amplifier is commonly used as a frequency multiplier? |
| A. | class a |
| B. | class b |
| C. | class c |
| D. | all of the above |
| Answer» D. all of the above | |
| 28. |
The of a common collector configuration is unity |
| A. | voltage gain |
| B. | current gain |
| C. | power gain |
| D. | input impedance |
| Answer» B. current gain | |
| 29. |
Consider a zener diode with a slope resistance of 10 Ω in series with a 90 Ω resistor fed from a dc supply containing a ripple voltage of 20mV peak-to-peak. Compute for the ripple voltage in load |
| A. | 1 mv p-p |
| B. | 2 mv p-p |
| C. | 1 v p-p |
| D. | 6mv p-p |
| Answer» C. 1 v p-p | |
| 30. |
The ratio output rms power in watts to the input dc power in watts in the different amplifier class is called . |
| A. | gain |
| B. | amplification factor |
| C. | efficiency |
| D. | phase power |
| Answer» D. phase power | |
| 31. |
The impedance of a load must match the impedance of the amplifier so that |
| A. | minimum power is transferred to the load |
| B. | the efficiency can be maintained at low level |
| C. | the signal-to- noise ratio is maximized |
| D. | maximum power is transferred to the load |
| Answer» E. | |
| 32. |
The fan out of a MOS logic gate is higher than that of TTL gates because of its |
| A. | low input impedance |
| B. | high output impedance |
| C. | low output impedance |
| D. | high input impedance |
| Answer» E. | |
| 33. |
An amplifier without feedback has a voltage gain of 50, input resistance is 1 KΩ & Output resistance of 2.5KΩ.The input resistance of the current-shunt negative feedback amplifier using the above amplifier with a feedback factor of 0.2 is |
| A. | 1/11kΩ |
| B. | 1/5kΩ |
| C. | 5kΩ |
| D. | 11kΩ |
| Answer» C. 5kΩ | |
| 34. |
The maximum current for a LOW output on a standard TTL gate is |
| A. | 16 µa. |
| B. | 40 ma. |
| C. | 100 µa. |
| D. | 16 ma. |
| Answer» E. | |
| 35. |
The maximum current for a HIGH output on a standard TTL gate is |
| A. | -10 µa. |
| B. | -400 µa. |
| C. | -1 µa. |
| D. | -10 ma. |
| Answer» C. -1 µa. | |
| 36. |
The major advantage of TTL logic circuits over CMOS is |
| A. | lower propagation delay. |
| B. | the ability to output higher voltages. |
| C. | more modern design. |
| D. | very low power consumption |
| Answer» B. the ability to output higher voltages. | |
| 37. |
The difference between VOH and VIH voltages is known as |
| A. | input margin. |
| B. | noise margin. |
| C. | output differential. |
| D. | input level. |
| Answer» C. output differential. | |
| 38. |
The lower transistor of a totem-pole output is OFF when the gate output is |
| A. | high. |
| B. | malfunctioning. |
| C. | low. |
| D. | over driven. |
| Answer» B. malfunctioning. | |
| 39. |
Unused inputs on TTL, AND, and NAND gates |
| A. | degrade the gate\s noise immunity. |
| B. | if left open will have the same effect as high inputs. |
| C. | should be tied high. |
| D. | all of the above are correct. |
| Answer» E. | |
| 40. |
The upper transistor of a totem-pole output is OFF when the gate output is |
| A. | logic 1. |
| B. | malfunctioning. |
| C. | high. |
| D. | low. |
| Answer» E. | |
| 41. |
Which of the following is not a common logic family used today? |
| A. | rtl |
| B. | ecl |
| C. | ttl |
| D. | cmos |
| Answer» B. ecl | |
| 42. |
The output current for a LOW output is called a(n) |
| A. | exit current. |
| B. | sink current. |
| C. | ground current. |
| D. | fan-out. |
| Answer» C. ground current. | |
| 43. |
Which of the following is not a solution to interface problems between CMOS and TTL? |
| A. | pull-up resistor |
| B. | pull-down resistor |
| C. | level-shifter |
| D. | buffer |
| Answer» C. level-shifter | |
| 44. |
Which of the following is a concern when using CMOS type devices? |
| A. | mechanical shock |
| B. | electrostatic discharge |
| C. | fan out |
| D. | under voltage |
| Answer» C. fan out | |
| 45. |
The superposition theorem requires as many circuits to be solved as there are |
| A. | sources, nodes and meshes |
| B. | sources and nodes |
| C. | sources |
| D. | nodes |
| Answer» D. nodes | |
| 46. |
The number of independent equations to solve a network is equal to |
| A. | the number of chords |
| B. | the number of branches |
| C. | sum of the number of branches and chords |
| D. | sum of number of branches, chords and nodes |
| Answer» B. the number of branches | |
| 47. |
While calculating Rth in Thevenin's theorem and Norton equivalent |
| A. | all independent sources are made dead |
| B. | only current sources are made dead |
| C. | only voltage sources are made dead |
| D. | all voltage and current sources are made dead |
| Answer» B. only current sources are made dead | |
| 48. |
A star circuit has element of resistance R/2. The equivalent delta elements will be |
| A. | r/6 |
| B. | fi? |
| C. | 2r |
| D. | 4r |
| Answer» C. 2r | |
| 49. |
A linear resistor having 0 < R < °o is a |
| A. | current controlled resistor |
| B. | voltage controlled resistor |
| C. | both current controlled and voltage controlled resistor |
| D. | none of the above |
| Answer» D. none of the above | |
| 50. |
A closed path made by several branches of the network is known as |
| A. | branch |
| B. | loop |
| C. | circuit |
| D. | junction |
| Answer» C. circuit | |