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. |
In a CE amplifier it is desired that the signal should be able to swing equally in both directions. Then the Q point should be |
| A. | at the centre of ac load line |
| B. | at the centre of dc load line |
| C. | at the centre of collector voltage |
| D. | at the centre of collector current |
| Answer» B. at the centre of dc load line | |
| 2. |
The common gate amplifier has a characteristically __________ input resistance and a __________ output resistance. |
| A. | low, low |
| B. | high, high |
| C. | low, high |
| D. | high, low |
| Answer» D. high, low | |
| 3. |
For input and later stages, BI-FET op-amp use |
| A. | JFETs and MOSFETs respectively |
| B. | MOSFETs and JFETs respectively |
| C. | JFETs and BJTs respectively |
| D. | BJTs and JFETs respectively |
| Answer» D. BJTs and JFETs respectively | |
| 4. |
The emitter coupled pair of BJT's gives a linear transfer relation between the differential output voltage and the differential input voltage Vid only when the magnitude of Vid is less a times the thermal voltage, where a is |
| A. | 4 |
| B. | 3 |
| C. | 2 |
| D. | 1 |
| Answer» E. | |
| 5. |
In most transistor the collector region is made physically larger than the emitter region |
| A. | for dissipating heat |
| B. | to distinguish it from other regions |
| C. | as it is sensitive to ultraviolet rays |
| D. | to reduce resistance in the path of flow of electrons |
| Answer» B. to distinguish it from other regions | |
| 6. |
The leakage current in CB configuration may be around |
| A. | few micro amperes |
| B. | few hundred micro amperes |
| C. | few milliamperes |
| D. | few hundred milliamperes |
| Answer» B. few hundred micro amperes | |
| 7. |
Assertion (A): A class C amplifier can also be used as frequency multiplierReason (R): When narrow current pulses drive a resonant circuit the output can be a near perfect sine wave |
| A. | Both A and R are correct and R is correct explanation for A |
| B. | Both A and R are correct but R is not correct explanation for A |
| C. | A is correct R is wrong |
| D. | A is wrong R is correct |
| Answer» C. A is correct R is wrong | |
| 8. |
A certain transistor has adc of 0.98 and a collectors leakage current of 5 A. If IE = 1 mA, the base current will be |
| A. | 35 A |
| B. | 25 A |
| C. | 15 A |
| D. | 5 A |
| Answer» D. 5 A | |
| 9. |
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. | |
| 10. |
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 | |
| 11. |
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 | |
| 12. |
The signal input to a given amplifier is made up of 100 mΩ signal power and 1 mΩ noise power. The amplifier contributes an additional 100 mΩ of noise and has a power gain of 20 dB. The input signal-to noise ratio is |
| A. | 2 |
| B. | 10 |
| C. | 20 |
| D. | 100 |
| Answer» E. | |
| 13. |
In switching devices, gold doping is used to |
| A. | improve bonding |
| B. | reduce storage time |
| C. | increase the mobility of the carrier |
| D. | protect the terminals against cooperation |
| Answer» C. increase the mobility of the carrier | |
| 14. |
Figure represents a |
| A. | NPN transistor |
| B. | PNP transistor |
| C. | Zener diode |
| D. | Power diode |
| Answer» B. PNP transistor | |
| 15. |
Assertion (A): A good op-amp should have very large band widthReason (R): An ideal op-amp should have infinite input resistance and zero output resistance |
| A. | Both A and R are correct and R is correct explanation for A |
| B. | Both A and R are correct but R is not correct explanation for A |
| C. | A is correct R is wrong |
| D. | A is wrong R is correct |
| Answer» B. Both A and R are correct but R is not correct explanation for A | |
| 16. |
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 | |
| 17. |
In a BJT amplifier circuit the size of coupling capacitor depends on |
| A. | lowest frequency |
| B. | highest frequency |
| C. | average of lowest and highest frequencies |
| D. | none of the above |
| Answer» B. highest frequency | |
| 18. |
In a closed loop non-inverting amplifier, constructed using single break-frequency op-amp, bandwidth with feedback can be written as. (f0 - break frequency, - gain of the feedback circuit, A - open loop voltage gain, Af - closed loop voltage gain) |
| A. | <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/329-470-1.png"> |
| B. | <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/329-470-2.png"> |
| C. | <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/329-470-3.png"> |
| D. | <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/329-470-4.png"> |
| Answer» B. <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/329-470-2.png"> | |
| 19. |
A FET is a __________ controlled device whereas a bipolar transistor is a __________ controlled device. |
| A. | gate, drain |
| B. | drain, gate |
| C. | current, voltage |
| D. | voltage, current |
| Answer» E. | |
| 20. |
A silicon sample A is doped with 1018 Atoms/cm3 of Boron. Another sample B of identical dimensions is doped with 1018 atoms/cm3 of phosphorus. The ratio of electron to hole mobility is 3. The ratio of conductivity of the sample A to B is |
| A. | 3 |
| B. | 1/3 |
| C. | 2/3 |
| D. | 3/2 |
| Answer» C. 2/3 | |
| 21. |
Assertion (A): If power gain doubles the power gain increases by 3 dBReason (R): The bel power gain of cascaded stages is equal to sum of each bel power gain |
| A. | Both A and R are correct and R is correct explanation for A |
| B. | Both A and R are correct but R is not correct explanation for A |
| C. | A is correct R is wrong |
| D. | A is wrong R is correct |
| Answer» B. Both A and R are correct but R is not correct explanation for A | |
| 22. |
In a class C amplifier, full cycle conductor of the current is achieved by employing |
| A. | tuned circuit |
| B. | transformers |
| C. | complementary pair |
| D. | Push pull configuration |
| Answer» B. transformers | |
| 23. |
Higher order active filters are used for variable |
| A. | bandwidth |
| B. | gain in the pass band |
| C. | impedance |
| D. | roll off rate |
| Answer» E. | |
| 24. |
Overall efficiency of class B amplifier is |
| A. | 72% |
| B. | 75% |
| C. | 78.5% |
| D. | 70% |
| Answer» D. 70% | |
| 25. |
For a transistor to have-a larger it must have and a |
| A. | close to zero |
| B. | close to 0.5 |
| C. | close to unity |
| D. | nearly infinite |
| Answer» D. nearly infinite | |
| 26. |
JFET is also known as |
| A. | linear device |
| B. | square law device |
| C. | inverse law device |
| D. | logarithmic law device |
| Answer» C. inverse law device | |
| 27. |
Drain feedback bias is often used with |
| A. | D MOSFETs |
| B. | E MOSFETs |
| C. | both D and E MOSFETs |
| D. | neither D nor E MOSFETs |
| Answer» C. both D and E MOSFETs | |
| 28. |
The ac collector current is nearly equal to |
| A. | ac base current |
| B. | ac signal current |
| C. | ac supply current |
| D. | ac emitter current |
| Answer» E. | |
| 29. |
From a measurement of the rise time of the output pulse of an amplifier whose input is a small amplitude square wave, one can estimate the following parameter of the amplifier |
| A. | gain bandwidth product |
| B. | slew rate |
| C. | upper 3 dB frequency |
| D. | lower 3 dB frequency |
| Answer» D. lower 3 dB frequency | |
| 30. |
In an amplifier, if the output current flows for 120 of the input cycle, the class of amplifier will be |
| A. | A |
| B. | B |
| C. | C |
| D. | AB |
| Answer» D. AB | |
| 31. |
Assertion (A): If we overdrive an amplifier the output signal may get clippedReason (R): To dissipate heat to atmosphere a heat sink is sometimes attached to the case of transistor |
| A. | Both A and R are correct and R is correct explanation for A |
| B. | Both A and R are correct but R is not correct explanation for A |
| C. | A is correct R is wrong |
| D. | A is wrong R is correct |
| Answer» C. A is correct R is wrong | |
| 32. |
Which op-amp circuit uses a diode as one of the circuit components? |
| A. | Integrating amplifier |
| B. | Differentiating amplifier |
| C. | Logarithmic amplifier |
| D. | Summing amplifier |
| Answer» D. Summing amplifier | |
| 33. |
High cut off frequency can be expected in case of |
| A. | common-base |
| B. | common-emitter |
| C. | common-collector |
| D. | all of the above |
| Answer» D. all of the above | |
| 34. |
Which coupling produces the minimum interference with frequency response? |
| A. | RC coupling |
| B. | Transformer coupling |
| C. | Direct coupling |
| D. | Impedance coupling |
| Answer» D. Impedance coupling | |
| 35. |
A generator with an internal resistance of 600 &ohm; drives an amplifier whose input resistance is 400 &ohm;. The generator's open circuit voltages is 1 mV; the amplifier develops 100mV across an 8k&ohm; load. The input voltage to the amplifier is |
| A. | 0.1 m V |
| B. | 0.4 m V |
| C. | 1 m V |
| D. | 4 m V |
| Answer» C. 1 m V | |
| 36. |
Assertion (A): A sine wave with slew rate distortion looks rectangularReason (R): The maximum rate of output voltage change is called slew rate |
| A. | Both A and R are correct and R is correct explanation for A |
| B. | Both A and R are correct but R is not correct explanation for A |
| C. | A is correct R is wrong |
| D. | A is wrong R is correct |
| Answer» E. | |
| 37. |
In a P-N-P transistor, electrons flow |
| A. | into the transistor at the collector only |
| B. | into the transistor at the base and the collector leads |
| C. | out of the transistor at base and collector leads |
| D. | out of the transistor at base, collector as well as emitter leads |
| Answer» C. out of the transistor at base and collector leads | |
| 38. |
Tuned amplifiers are used at radio frequencies. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 39. |
The knee voltages in silicon and germanium diodes respectively are |
| A. | 0.3 V and 0.7 V |
| B. | 0.7 V and 0.3 V |
| C. | 0.7 V each |
| D. | 0.3 V each |
| Answer» C. 0.7 V each | |
| 40. |
In calculating input impedance, the load impedance is considered to be connected at the output. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 41. |
In a transistor dc is likely to vary between 100 and 400. The proper value of dc to be used to located Q point is |
| A. | 100 |
| B. | 400 |
| C. | 250 |
| D. | 200 |
| Answer» E. | |
| 42. |
Assertion (A): The duty cycle of a class C amplifier affects the power dissipation of transistorReason (R): At higher harmonics the efficiency of a class C amplifier becomes poor |
| A. | Both A and R are correct and R is correct explanation for A |
| B. | Both A and R are correct but R is not correct explanation for A |
| C. | A is correct R is wrong |
| D. | A is wrong R is correct |
| Answer» C. A is correct R is wrong | |
| 43. |
If the op-amp in figure has a unity gain frequency of 1 MHz, the cut off frequency is |
| A. | 100 kHz |
| B. | 1 MHz |
| C. | 10 MHz |
| D. | 90 MHz |
| Answer» B. 1 MHz | |
| 44. |
In a self bias circuit for CE amplifier the collector supply voltage is made twice. The collector current will |
| A. | decrease |
| B. | increase |
| C. | remain the same |
| D. | increase or decrease |
| Answer» C. remain the same | |
| 45. |
In a full wave voltage doubler circuit, the input frequency is 560 Hz. The ripple frequency is |
| A. | 25 Hz |
| B. | 50 Hz |
| C. | 100 Hz |
| D. | 200 Hz |
| Answer» D. 200 Hz | |
| 46. |
Assertion (A): A tuned amplifier uses a parallel tuned circuitReason (R): A tuned amplifier is used to amplify a narrowband frequencies |
| A. | Both A and R are correct and R is correct explanation for A |
| B. | Both A and R are correct but R is not correct explanation for A |
| C. | A is correct R is wrong |
| D. | A is wrong R is correct |
| Answer» B. Both A and R are correct but R is not correct explanation for A | |
| 47. |
Assertion (A): The main use of Miller integrator is to generate rampReason (R): An inverting amplifier can handle more than one input at the same time. |
| A. | Both A and R are correct and R is correct explanation for A |
| B. | Both A and R are correct but R is not correct explanation for A |
| C. | A is correct R is wrong |
| D. | A is wrong R is correct |
| Answer» C. A is correct R is wrong | |
| 48. |
In a transistor leakage current mainly depends on |
| A. | doping of base |
| B. | size of emitter |
| C. | rating of transistor |
| D. | temperature |
| Answer» E. | |
| 49. |
In a CB amplifier the maximum efficiency could be |
| A. | 99% |
| B. | 85% |
| C. | 50% |
| D. | 25% |
| Answer» E. | |
| 50. |
Assertion (A): As per Miller theorem a capacitance C from input to output appears as a much larger capacitance across input terminalsReason (R): In a lag network the output voltage appears across capacitor |
| A. | Both A and R are correct and R is correct explanation for A |
| B. | Both A and R are correct but R is not correct explanation for A |
| C. | A is correct R is wrong |
| D. | A is wrong R is correct |
| Answer» C. A is correct R is wrong | |