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. |
Increasing the collector supply voltage will increase |
| A. | Base current |
| B. | Collector current |
| C. | Emitter current |
| D. | None of these |
| Answer» E. | |
| 2. |
The transconductance gm of the transistor shown below in figure is 10 mS. The value of the input resistance R |
| A. | 10 0 k |
| B. | 8 3 k |
| C. | 5 0 k |
| D. | 2 5 k |
| Answer» D. 2 5 k | |
| 3. |
In a normally biased npn transistor, the electrons in the emitter have enough energy to overcome the barrier potential of the |
| A. | Base-emitter junction |
| B. | Base-collector junction |
| C. | Collector-base junction |
| D. | Recombination path |
| Answer» B. Base-collector junction | |
| 4. |
When a free electron recombines with a hole in the base region, the free electron becomes |
| A. | Another free electron |
| B. | A Valence electron |
| C. | A conduction-band electron |
| D. | A majority carrier |
| Answer» C. A conduction-band electron | |
| 5. |
The perfectly matched silicon transistors are connected as shown in figure below. The value of current I will be |
| A. | 0 mA |
| B. | 2 3 mA |
| C. | 4 3 mA |
| D. | 7 3 mA |
| Answer» D. 7 3 mA | |
| 6. |
Consider the transistor circuit given below. It is desired to have V |
| A. | 1 k |
| B. | 500 |
| C. | 2 k |
| D. | 3 k |
| Answer» C. 2 k | |
| 7. |
In the active region, the collector current is not changed significantly by |
| A. | Base supply voltage |
| B. | Base current |
| C. | Current gain |
| D. | Collector resistance |
| Answer» D. Collector resistance | |
| 8. |
Consider the regulated power supply given below: |
| A. | 25 3 V |
| B. | 29 4 V |
| C. | 27 8 V |
| D. | 30 5 V |
| Answer» C. 27 8 V | |
| 9. |
The specification for a silicon transistor are: I |
| A. | 92 ohms, 75 mhos |
| B. | 40 ohms, 118 mhos |
| C. | 12 5 ohms, 12 mhos |
| D. | 112 ohms, 10 2 mhos |
| Answer» D. 112 ohms, 10 2 mhos | |
| 10. |
The common emitter amplifier shown in the figure below is biased using a 1 mA ideal current source. The approximate base current value is |
| A. | 0 A |
| B. | 10 A |
| C. | 100 A |
| D. | 1000 A |
| Answer» C. 100 A | |
| 11. |
AC emitter resistance equals 25 mV divided by the |
| A. | Quiescent base current |
| B. | DC emitter current |
| C. | AC emitter current |
| D. | Change in collector current |
| Answer» C. AC emitter current | |
| 12. |
The ac equivalent circuit is derived from the original circuit by shorting all |
| A. | Resistors |
| B. | Capacitors |
| C. | Inductors |
| D. | Transistors |
| Answer» C. Inductors | |
| 13. |
Reducing all dc sources to zero is one of the steps in getting the |
| A. | dc equivalent circuit |
| B. | ac equivalent circuit |
| C. | complete amplifier circuit |
| D. | voltage divider biasing circuit |
| Answer» C. complete amplifier circuit | |
| 14. |
The capacitors of a CE amplifier appear to be |
| A. | Open to ac |
| B. | Shorted to dc |
| C. | Open to supply voltage |
| D. | Shorted to ac |
| Answer» E. | |
| 15. |
The gain of a bipolar transistor drops at high frequencies. This is because of the |
| A. | Coupling and bypass capacitors |
| B. | Early effect |
| C. | Inter-electrode transistor capacitances |
| D. | Coupling and bypass capacitors, and interelectrode transistor capacitances |
| Answer» B. Early effect | |
| 16. |
The widths of the base in a GaAs transistor and in a Si transistor (both n-p-n type) are equal. GaAs transistor works at higher frequency |
| A. | The band gap of GaAs is higher than that of Si |
| B. | The base transit time is lower in GaAs |
| C. | The negative differential mobility in GaAs favours operational very high frequency |
| D. | Si transistor works at higher frequency compared to GaAs transistor |
| Answer» D. Si transistor works at higher frequency compared to GaAs transistor | |
| 17. |
In a transistor amplifier, the reverse saturation current I |
| A. | Doubled for every 10 C rise in temperature |
| B. | Doubled for every 1 C rise in temperature |
| C. | Increased linearly with temperature |
| D. | Doubled for every 5 C rise in temperature |
| Answer» B. Doubled for every 1 C rise in temperature | |
| 18. |
From a measurement of the rise time of the output pulse on an amplifier whose input is a small amplitude square wave, one can estimate which of 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 | |
| 19. |
The phase difference between the input and output voltages in a common base arrangement is |
| A. | 180 |
| B. | 90 |
| C. | 270 |
| D. | 0 |
| Answer» E. | |
| 20. |
Most of the majority carriers from emitter |
| A. | Recombine in the base |
| B. | Recombine in the emitter |
| C. | Pass through the base region to the collector |
| D. | None of the above |
| Answer» D. None of the above | |
| 21. |
At the base emitter junction of a transistor, one finds |
| A. | Reverse bias |
| B. | A wide depletion layer |
| C. | Low resistance |
| D. | None of these |
| Answer» D. None of these | |
| 22. |
In a p-n-p transistor, current carriers are |
| A. | Acceptor ions |
| B. | Donor ions |
| C. | Free electrons |
| D. | Holes |
| Answer» E. | |
| 23. |
In a p-n-p transistor, in the base region, the main stream of current is |
| A. | Drift of holes |
| B. | Diffusion of holes |
| C. | Drift of electrons |
| D. | Diffusion of electrons |
| Answer» C. Drift of electrons | |
| 24. |
The device associated with voltage-controlled capacitance is a |
| A. | Light emitting diode |
| B. | Photodiode |
| C. | Varactor diode |
| D. | Zener diode |
| Answer» D. Zener diode | |
| 25. |
The conductivity of the emitter region of a BJT is kept |
| A. | Same as that of base region |
| B. | Much larger than that of base region |
| C. | Same as that of collector region |
| D. | Much smaller than that of base region |
| Answer» D. Much smaller than that of base region | |
| 26. |
The current through the zener diode in figure given below is |
| A. | 0 mA |
| B. | 3 3A |
| C. | 2 mA |
| D. | 20 mA |
| Answer» D. 20 mA | |
| 27. |
In a transistor if = 0.9, will be equal to |
| A. | 1.0 |
| B. | 0.09 |
| C. | 0.90 |
| D. | 9.0 |
| Answer» E. | |
| 28. |
The arrow on the emitter of a transistor indicates |
| A. | The direction of electron flow |
| B. | The direction of displacement current |
| C. | The direction of conventional current flow |
| D. | The ground connections |
| Answer» D. The ground connections | |
| 29. |
Introducing a resistor in the emitter of a common amplifier stabilizers the dc operating point against variation is |
| A. | Only the temperature |
| B. | Only the of the transistor |
| C. | Both temperature and |
| D. | None of above |
| Answer» D. None of above | |
| 30. |
A transistor is said to be in quiescent state when |
| A. | No signal is applied to the input |
| B. | It is unbiased |
| C. | No currents are flowing |
| D. | Emitter junction bias is just equal to collector junction bias |
| Answer» B. It is unbiased | |
| 31. |
A BJT is said to be operated in the saturated region if |
| A. | Both the junctions are reverse biased |
| B. | Base-emitter junction is reverse biased and base-collector is forward biased |
| C. | Both junctions are forward biased |
| D. | None of these |
| Answer» D. None of these | |
| 32. |
Which is the most heavily doped region in a transistor? |
| A. | Emitter |
| B. | Collector |
| C. | Base |
| D. | All regions are equally doped |
| Answer» B. Collector | |
| 33. |
n-p-n transistors prefered over p-n-p |
| A. | npn transistor is smaller in area |
| B. | Mobility of electron is higher than the hole |
| C. | Mobility of hole electron is higher than the hole electron |
| D. | None of the above |
| Answer» C. Mobility of hole electron is higher than the hole electron | |
| 34. |
For the circuit shown in figure the value of I |
| A. | 400 A |
| B. | 400 A |
| C. | 600 A |
| D. | 600 A |
| Answer» C. 600 A | |
| 35. |
For a transistor, the current gain relation between CB current gain a and CE current gain b is |
| A. | = (1 ) |
| B. | <table><tr><td rowspan="2"> = </td> <td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> </center></td></tr><td align="center">1 </td></table> |
| C. | = (1 + ) |
| D. | = (1 + ) |
| Answer» B. <table><tr><td rowspan="2"> = </td> <td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> </center></td></tr><td align="center">1 </td></table> | |
| 36. |
For a transistor = 40 and I |
| A. | 1 mA |
| B. | 0.975 mA |
| C. | 1.025 mA |
| D. | None of these |
| Answer» D. None of these | |
| 37. |
The region of operation of the transistor in the circuit below is |
| A. | Forward-active |
| B. | Reverse-active |
| C. | Saturation |
| D. | Cut-off |
| Answer» C. Saturation | |
| 38. |
Most of the transistors are npn type and not pnp type because |
| A. | npn transistor gives large voltage gain |
| B. | npn transistors a more negative than pnp transistors |
| C. | In transistor, the current conduction is by free electrons which are less mobile than holes |
| D. | We can have high conduction in npn transistors. |
| Answer» E. | |
| 39. |
The highest area in a transistor |
| A. | Emitter |
| B. | Base |
| C. | Collector |
| D. | All |
| Answer» D. All | |
| 40. |
When the light increases, the reverse minority carrier current in a photodiode |
| A. | Decreases |
| B. | Increases |
| C. | Is unaffected |
| D. | Reverse direction |
| Answer» C. Is unaffected | |
| 41. |
The most noticeable effect of a small increase in temperature in the common emitter connected transistor is |
| A. | The increase in the ac current gain |
| B. | The decrease in the ac current gain |
| C. | The increase in output resistance |
| D. | The increase in I |
| E. | <sub>CEO </sub> |
| Answer» E. <sub>CEO </sub> | |
| 42. |
For above question I |
| A. | 1 pA |
| B. | 2 pA |
| C. | 3 pA |
| D. | 50 pA |
| Answer» B. 2 pA | |
| 43. |
When determining the common-emitter current gain by making small changes in direct currents, the collector voltage is held constant so that |
| A. | The output resistance will be high |
| B. | The transistor will not burn out |
| C. | The change in emitter current will be due to a change in collector current |
| D. | The change in collector current will be due to a change in base current |
| Answer» E. | |
| 44. |
cut-off frequency of a bipolar junction transistor increases with the |
| A. | Increase in base width |
| B. | Increase in emitter width |
| C. | Increase in the collector width |
| D. | Decrease in the base width |
| Answer» B. Increase in emitter width | |
| 45. |
A photodiode is normally |
| A. | Forward-biased |
| B. | Reverse-biased |
| C. | Neither-forward-nor reverse-biased |
| D. | Emitting light |
| Answer» C. Neither-forward-nor reverse-biased | |
| 46. |
The number of depletion layers in a transistor is |
| A. | Four |
| B. | Three |
| C. | One |
| D. | Two |
| Answer» E. | |
| 47. |
Breakdown does not destroy a zener diode, provided the zener current is less than the |
| A. | Breakdown voltage |
| B. | Zener test current |
| C. | Maximum zener current rating |
| D. | Barrier potential |
| Answer» D. Barrier potential | |
| 48. |
Under high electric fields, in a semiconductor increasing electric field |
| A. | 1 and 4 only |
| B. | 1 and 3 only |
| C. | All of the above |
| D. | None of these |
| Answer» C. All of the above | |
| 49. |
When the zener voltage increases in a zener regulator, which of these currents remains approximately constant? |
| A. | Series current |
| B. | Zener current |
| C. | Load current |
| D. | Total current |
| Answer» E. | |
| 50. |
Reverse recovery current in a diode depends upon |
| A. | Forward field current |
| B. | Storage charge |
| C. | Temperature |
| D. | PIV |
| Answer» B. Storage charge | |