MCQOPTIONS
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MCQOPTIONS
This section includes 46 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering Questions knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
In deriving ac equivalent circuit for an amplifier circuit, we short circuit___________? |
| A. | all resistors |
| B. | all transistors |
| C. | all inductors |
| D. | all capacitors |
| Answer» E. | |
| 2. |
In a transistor leakage current mainly depends on__________? |
| A. | doping of base |
| B. | size of emitter |
| C. | rating of transistor |
| D. | temperature |
| Answer» E. | |
| 3. |
A 741-type OP-AMP has a gain-bandwidth product of 1MHz. A non-inverting amplifier using this op-amp & having a voltage gain of 20db will exhibit -3db bandwidth of__________? |
| A. | 50 KHz |
| B. | 100KHz |
| C. | 1000/17 KHz |
| D. | 1000/7.07 KHz |
| Answer» C. 1000/17 KHz | |
| 4. |
When a transistor is connected in common emitter mode, it with have__________? |
| A. | negligible input resistance and high output resistance |
| B. | high input resistance and low output resistance |
| C. | medium input resistance and high output resistance |
| D. | low input resistance as well as output resistance |
| Answer» D. low input resistance as well as output resistance | |
| 5. |
The early effect in a bipolar junction transistor is caused by_______________? |
| A. | fast turn-on |
| B. | fast turn-off |
| C. | large collector-base reverse bias |
| D. | large emitter-base forward bias |
| Answer» D. large emitter-base forward bias | |
| 6. |
Thermal runaway is not possible in FET because as the temperature of FET increases_________________? |
| A. | the mobility decreases |
| B. | the transconductance increases |
| C. | the drain current increases |
| D. | none of the above |
| Answer» B. the transconductance increases | |
| 7. |
Which of the following is not associated with a p-n junction? |
| A. | junction capacitance |
| B. | charge storage capacitance |
| C. | depletion capacitance |
| D. | channel length modulation |
| Answer» E. | |
| 8. |
A change in the value of the emitter resistance Re in a differential amplifier? |
| A. | affects the difference mode gain Ad |
| B. | affects the common mode gain Ac |
| C. | affects both Ad and Ac |
| D. | does not effect either Ad and Ac |
| Answer» C. affects both Ad and Ac | |
| 9. |
The current gain of a BJT is__________? |
| A. | gm r0 |
| B. | gm / r0 |
| C. | gm rπ |
| D. | gm /rπ |
| Answer» D. gm /rπ | |
| 10. |
A constant current signal across a parallel RLC circuits gives an o/p of 1.4v at the signal frequency of 3.89KHZ and 4.1KHZ .At the frequency of 4KHZ,the o/p voltage will be___________? |
| A. | 1 v |
| B. | 2v |
| C. | 1.4v |
| D. | 2.8v |
| Answer» C. 1.4v | |
| 11. |
An amplifier without feedback has a voltage gain of 50,input resistance os 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» B. 1/5KΩ | |
| 12. |
In a p-n junction diode under reverse bias , the magnitude of electric field is maximum at_____________? |
| A. | the edge of the depletion region on the p-side |
| B. | the edge of the depletion region on the n-side |
| C. | the p-n junction |
| D. | the center of the depletion region on the n-side |
| Answer» D. the center of the depletion region on the n-side | |
| 13. |
To prevent a DC return between source and load, it is necessary to use___________? |
| A. | resistor between source and load |
| B. | inductor between source and load |
| C. | capacitor between source and load |
| D. | either A. or B. |
| Answer» D. either A. or B. | |
| 14. |
The bandwidth of an RF tuned amplifier is dependent on____________? |
| A. | Q –factor of the tuned o/p circuit |
| B. | Q –factor of the tuned i/p circuit |
| C. | Quiescent operating point |
| D. | Q-factor of the o/p and i/p circuits as well as quiescent operating point |
| Answer» B. Q –factor of the tuned i/p circuit | |
| 15. |
An ideal OP-AMP is an ideal___________? |
| A. | Current controlled Current source |
| B. | Current controlled voltage source |
| C. | Voltage controlled voltage source |
| D. | voltage controlled current source |
| Answer» C. Voltage controlled voltage source | |
| 16. |
Voltage Series feedback also called series-shunt feedback) results in__________? |
| A. | Increase in both input & output impedances |
| B. | Decreases in both input & output impedances |
| C. | Increase in input impedance & decreases in output impedance |
| D. | Decrease in input impedance & increase in output impedance |
| Answer» D. Decrease in input impedance & increase in output impedance | |
| 17. |
A dc power supply has no-load voltage of 30v,and a full-load voltage of 25v at full-load current of 1A.Its output resistance & load regulation ,respectively are_____________? |
| A. | 5 Ω & 20 % |
| B. | 25 Ω & 20 % |
| C. | 5 Ω & 16.7 % |
| D. | 25 Ω & 16.7 % |
| Answer» C. 5 Ω & 16.7 % | |
| 18. |
In an op-amp differentiator:________________? |
| A. | the amplitude of output is proportional to rate of change of input |
| B. | the amplitude of output is proportional to input |
| C. | output occurs when input is finite and constant |
| D. | polarity of input and output is the same |
| Answer» B. the amplitude of output is proportional to input | |
| 19. |
Most of the linear ICs are based on the two-transistor differential amplifier because of its___________? |
| A. | input voltage dependent linear transfer characteristic |
| B. | high voltage gain |
| C. | high input resistance |
| D. | high CMRR |
| Answer» E. | |
| 20. |
In the differential voltage gain & the common mode voltage gain of a differential amplifier are 48db &2db respectively, then its common mode rejection ratio is__________? |
| A. | 23dB |
| B. | 25dB |
| C. | 46dB |
| D. | 50dB |
| Answer» D. 50dB | |
| 21. |
A differential amplifier has a differential gain of 20,000 . CMRR=80 dB. The common mode gain is given by________? |
| A. | 2 |
| B. | 1 |
| C. | 1/2 |
| D. | 0 |
| Answer» B. 1 | |
| 22. |
In a full-wave rectifier using two ideal diodes,Vdc & Vm are the dc & peak values of the voltage respectively across a resistive load. If PIV is the peak inverse voltage of the diode, then the appropriate relationships for this rectifier is____________? |
| A. | Vdc = Vm/π, PIV=2Vm |
| B. | Vdc = 2Vm/π, PIV=2vm |
| C. | Vdc = 2Vm/π, PIV=Vm |
| D. | Vdc = Vm/π, PIV=Vm |
| Answer» C. Vdc = 2Vm/π, PIV=Vm | |
| 23. |
The MOSFET switch in its on-state may be considered equivalent to_____________? |
| A. | resistor |
| B. | inductor |
| C. | capacitor |
| D. | battery |
| Answer» D. battery | |
| 24. |
In a CB amplifier the maximum efficiency could be____________? |
| A. | 99% |
| B. | 85% |
| C. | 50% |
| D. | 25% |
| Answer» E. | |
| 25. |
The most commonly used amplifier in sample & hold circuits is______________? |
| A. | A unity gain non-inverting amplifier |
| B. | A unity gain inverting amplifier |
| C. | An inverting amplifier with a gain of 10 |
| D. | An inverting amplifiers with a gain of 100 |
| Answer» C. An inverting amplifier with a gain of 10 | |
| 26. |
The horizontal intercept of dc load line is the same as ideal____________? |
| A. | cut off point |
| B. | saturation point |
| C. | operating point |
| D. | quasi saturation point |
| Answer» B. saturation point | |
| 27. |
Introducing a resistor in the emitter of a common amplifier stabilizes the dc operating point against variations in____________? |
| A. | Only the temperature |
| B. | only the β of the transistor |
| C. | Both Temperature & β |
| D. | None of the above |
| Answer» D. None of the above | |
| 28. |
MOSFET can be used as a__________? |
| A. | current controlled capacitor |
| B. | voltage controlled capacitor |
| C. | current controlled inductor |
| D. | voltage controlled inductors |
| Answer» C. current controlled inductor | |
| 29. |
Which of the following amplifier circuit using junction transistor has the best gain? |
| A. | Common base |
| B. | Common emitter |
| C. | Common collector |
| D. | All have the same gain |
| Answer» C. Common collector | |
| 30. |
In a common emitter, unbypassed resister provides___________? |
| A. | voltage shunt feedback |
| B. | current series feedback |
| C. | negative voltage feedback |
| D. | positive current feedback |
| Answer» D. positive current feedback | |
| 31. |
If =0.98 ,Ico=6µA and Iβ=100µA for a transistor,then the value of Ic will be______? |
| A. | 2.3mA |
| B. | 3.2mA |
| C. | 4.6 mA |
| D. | 5.2mA |
| Answer» E. | |
| 32. |
A differential amplifier is invariably used in the i/p stage of all OP-amps. This is done basically to provide the OP-amps with a very high_________? |
| A. | CMMR |
| B. | Bandwidth |
| C. | Slew rate |
| D. | Open-loop gain |
| Answer» D. Open-loop gain | |
| 33. |
A source follower using an FET usually has a voltage gain which is___________? |
| A. | greater than +100 |
| B. | slightly less than unity but positive |
| C. | exactly unity but negative |
| D. | about -10 |
| Answer» B. slightly less than unity but positive | |
| 34. |
An n- channel JFET has IDSS=2mA,and Vp=-4v.Its transconductance gm=in mA/V)for an applied gate to source voltage VGS=-2v is___________? |
| A. | 0.25 |
| B. | 0.5 |
| C. | 0.75 |
| D. | 1 |
| Answer» C. 0.75 | |
| 35. |
An OPAMP has a slew rate of 5 V/μ S .The largest sine wave O/P voltage possible at a frequency of 1 MHZ is [Hint: Slew rate is defined as the max. rate of change of output voltage. Its unit is V/μS. |
| A. | 10 volts |
| B. | 5 volts |
| C. | 5/1 volts |
| D. | 5/2 volts |
| Answer» E. | |
| 36. |
The effective channel length of a MOSFET in a saturation decreases with increase in___________? |
| A. | Gate voltage |
| B. | Drain voltage |
| C. | Source voltage |
| D. | Body voltage |
| Answer» C. Source voltage | |
| 37. |
Class AB operation is often used in power large signal amplifiers in order to_________? |
| A. | get maximum efficiency |
| B. | remove even harmonics |
| C. | overcome a crossover distortion |
| D. | reducing collector dissipation |
| Answer» D. reducing collector dissipation | |
| 38. |
The current gain of a bipolar transistor drops at high frequencies because of____________? |
| A. | Transistor capacitances |
| B. | High current effects in the base |
| C. | Parasitic inductive elements |
| D. | The early effect |
| Answer» B. High current effects in the base | |
| 39. |
Negative feedback in an amplifier____________? |
| A. | Reduces gain |
| B. | Increase frequency &phase distortion |
| C. | Reduces bandwidth |
| D. | Increases noise |
| Answer» B. Increase frequency &phase distortion | |
| 40. |
The cascade amplifier is a multistage configuration of__________? |
| A. | CC-CB |
| B. | CE-CB |
| C. | CB-CC |
| D. | CE-CC |
| Answer» C. CB-CC | |
| 41. |
The encapsulation of transistor is necessary for__________? |
| A. | preventing radio interference |
| B. | preventing photo-emission effects |
| C. | avoiding loss of free electrons |
| D. | mechanical ruggedness |
| Answer» E. | |
| 42. |
An amplifier using an opamp with slew rate SR=1v/µsec has a gain of 40db.if this amplifier has to faithfully amplify sinusoidal signals from dc to 20 KHz without introducing any slew-rate induced distortion, then the input signal level must not exceed________? |
| A. | 795mV |
| B. | 395mV |
| C. | 795 mV |
| D. | 39.5mV |
| Answer» D. 39.5mV | |
| 43. |
Generally, the gain of a transistor amplifier falls at high frequencies due to the___________? |
| A. | Internal Capacitance of the device |
| B. | Coupling capacitor at the input |
| C. | Skin effect |
| D. | Coupling capacitor at the output |
| Answer» B. Coupling capacitor at the input | |
| 44. |
An npn BJT has gm=38mA/v, cµ =10¯14 F, cπ =10¯13F and DC current gain β0=90.For this transistor fT & fβ are________? |
| A. | fT =1.64 x 108 Hz & fβ = 1.47 x 1010 Hz. |
| B. | fT =1.47 x 1010 Hz & fβ = 1.64 x 108 Hz |
| C. | fT =1.33 x 1012 Hz & fβ = 1.47 x 1010 Hz |
| D. | fT =1.47 x 1010 Hz & fβ = 1.33 x 1012 Hz |
| Answer» C. fT =1.33 x 1012 Hz & fβ = 1.47 x 1010 Hz | |
| 45. |
The action of JFET in its equivalent circuit can best be represented as a_____________? |
| A. | Current controlled Current source |
| B. | Current controlled voltage source |
| C. | Voltage controlled voltage source |
| D. | voltage controlled current source |
| Answer» E. | |
| 46. |
In all base driver amplifiers__________? |
| A. | ac collector voltage is 180° out of phase with ac base voltage |
| B. | ac emitter voltage is 180° out of phase with ac base voltage |
| C. | ac collector voltage is in phase with ac base voltage |
| D. | none of the above |
| Answer» B. ac emitter voltage is 180° out of phase with ac base voltage | |