MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 2171 Mcqs, each offering curated multiple-choice questions to sharpen your ENGINEERING SERVICES EXAMINATION (ESE) knowledge and support exam preparation. Choose a topic below to get started.
| 1401. |
In figure base current is 10 μA and βdc = 100. Then VE = |
| A. | 5 V |
| B. | 10 V |
| C. | 15 V |
| D. | 20 V |
| Answer» D. 20 V | |
| 1402. |
An op-amp integrating circuit uses |
| A. | an inductor |
| B. | a capacitor |
| C. | both inductor and capacitor |
| D. | none of the above |
| Answer» C. both inductor and capacitor | |
| 1403. |
Which one of the following devices is not used as the controller in a stabilizer? |
| A. | DIAC |
| B. | TRIAC |
| C. | SCR |
| D. | Power transistor |
| Answer» B. TRIAC | |
| 1404. |
Thermal runaway will take place if the quiescent point is such that |
| A. | VCE > 1/2VCC |
| B. | VCE < VCC |
| C. | VCE < 2VCC |
| D. | VCE < 1/2VCC |
| Answer» B. VCE < VCC | |
| 1405. |
An RC oscillator uses |
| A. | one RC combination |
| B. | two RC combinations |
| C. | at least three RC combinations |
| D. | either (a) or (b) |
| Answer» D. either (a) or (b) | |
| 1406. |
The input to integrating op-amp is a rectangular wave. The output will be |
| A. | a sine wave |
| B. | a rectangular wave |
| C. | a triangular wave |
| D. | none of the above |
| Answer» D. none of the above | |
| 1407. |
Emitter follower is in which of following configuration. |
| A. | common Base |
| B. | common Emitter |
| C. | common collector |
| D. | common Base or common Emitter |
| Answer» D. common Base or common Emitter | |
| 1408. |
A voltage doubler circuit is fed by a voltage Vm sin ωt. The output voltage will be nearly 2 Vm only if |
| A. | load resistance is small |
| B. | load resistance is large |
| C. | load resistance is neither small nor large |
| D. | either (a) or (c) |
| Answer» C. load resistance is neither small nor large | |
| 1409. |
Which of the following is necessary transistor action? |
| A. | The base region must be very wide |
| B. | The base region must be very narrow |
| C. | The base region must be made of some insulating material |
| D. | The collector region must be heavily doped |
| Answer» C. The base region must be made of some insulating material | |
| 1410. |
DC voltage of the order of a few mV can be accurately of measured by |
| A. | PMMC voltmeters |
| B. | moving iron voltmeter |
| C. | null balancing potentiometer |
| D. | electrostatic voltmeter |
| Answer» D. electrostatic voltmeter | |
| 1411. |
A power transistor dissipates 5 W. If ambient temperature is 30° and case to air thermal resistance is 10° C/W, the case temperature is |
| A. | 80°C |
| B. | 20°C |
| C. | 32°C |
| D. | 305°C |
| Answer» B. 20°C | |
| 1412. |
Class A and Class B power amplifiers predominate at |
| A. | audio frequencies |
| B. | radio frequencies |
| C. | all frequencies |
| D. | audio and radio frequency |
| Answer» B. radio frequencies | |
| 1413. |
Oscillation frequency in Wein bridge oscillator is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 1414. |
Assertion (A): An ac amplifier uses coupling capacitors at input and outputReason (R): The capacitive reactance varies inversely with frequency. It is infinite for dc |
| 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 | |
| 1415. |
Common emitter transistor has |
| A. | high current and high voltage gain |
| B. | low current gain and low voltage gain |
| C. | high current gain and low voltage gain |
| D. | low current and voltage gain |
| Answer» B. low current gain and low voltage gain | |
| 1416. |
The conversion or collector circuit efficiency is a measure |
| A. | how successfully the active device converts D.C. power to A.C. signal power |
| B. | how much distortion in output is reduced with respect to input |
| C. | how successfully the active device converts A.C. power to D.C. signal power |
| D. | none of the above |
| Answer» B. how much distortion in output is reduced with respect to input | |
| 1417. |
Which of the following best represents the output impedance of an actual op-amp? |
| A. | 10 ohm |
| B. | 100 ohm |
| C. | 10 k ohm |
| D. | 100 k ohm |
| Answer» C. 10 k ohm | |
| 1418. |
In the circuit of figure v1 = 8 V and v2 = 0. Which diode will conduct (Assume ideal diodes)? |
| A. | D1 only |
| B. | D2 only |
| C. | Both D1 and D2 |
| D. | Neither D1 nor D2 |
| Answer» B. D2 only | |
| 1419. |
Assertion (A): In CE amplifier the emitter is at ground potential for ac signalsReason (R): A CE amplifier has near unity voltage 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» D. A is wrong R is correct | |
| 1420. |
Figure shows basic Hartley oscillator configuration. Do you think the polarities marked for the split coiled are correct? |
| A. | yes they are |
| B. | no they are not |
| C. | it really doesn't matter |
| D. | none of the above |
| Answer» C. it really doesn't matter | |
| 1421. |
In the circuit of figure, PIV can be up to |
| A. | Em |
| B. | 2 Em |
| C. | 0.5 Em |
| D. | √2 Em |
| Answer» C. 0.5 Em | |
| 1422. |
Assertion (A): In a full wave rectifier output the lowest ac component is at twice the input frequencyReason (R): In a full wave rectifier, the output waveform consists of half sinusoids |
| 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 | |
| 1423. |
The output voltage waveform of a CE amplifier is fed to a dc coupled CRO. The trace on the screen will be |
| A. | dc output voltage |
| B. | ac output voltage |
| C. | sum of dc and ac output voltage |
| D. | either (a) or (b) |
| Answer» D. either (a) or (b) | |
| 1424. |
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 | |
| 1425. |
A clipper |
| A. | adds a dc component to the input signal |
| B. | removes signal voltages above or below a specified value |
| C. | both (a) and (b) |
| D. | either (a) or (b) |
| Answer» C. both (a) and (b) | |
| 1426. |
In a class C operation VCC = 30 V and VCE(sat) = 2 V. The efficiency is |
| A. | 93.75% |
| B. | 88% |
| C. | 6.66% |
| D. | 3.33% |
| Answer» B. 88% | |
| 1427. |
Which of the following oscillator circuits uses three capacitors in the phase shifting network? |
| A. | Hartley |
| B. | Clapp |
| C. | Colpitt's |
| D. | Both (b) and (c) |
| Answer» C. Colpitt's | |
| 1428. |
The zener diode in the rectangular circuit shown in the figure has a zener voltage of 5.8 volts and a zener knee current of 0.5 mA. The maximum load current drawn from this circuit ensuring proper functioning over the input voltage range between 20 and 30 volts, is |
| A. | 23.7 mA |
| B. | 14.2 mA |
| C. | 13.7 mA |
| D. | 24.2 mA |
| Answer» E. | |
| 1429. |
Gain stability in an oscillator can bs achieved by |
| A. | providing negative feedback |
| B. | providing positive feedback |
| C. | using low Q circuits |
| D. | controlling the gain |
| Answer» E. | |
| 1430. |
Two CE stages are coupled through a capacitor. To calculate the quiescent base current of the two transistors, the capacitor is treated as |
| A. | open circuit |
| B. | short circuit |
| C. | neither (a) nor (b) |
| D. | either (a) or (b) |
| Answer» B. short circuit | |
| 1431. |
N-channel FETs are superior to p-channel FETs because |
| A. | mobility of electrons is smaller than that of holes |
| B. | mobility of electrons is greater than that of holes |
| C. | they consume less power |
| D. | they have high switching time |
| Answer» C. they consume less power | |
| 1432. |
An ideal op-amp has |
| A. | infinite input and output resistance |
| B. | low input and output resistance |
| C. | low input and high output resistance |
| D. | infinite input resistance and zero output resistance |
| Answer» E. | |
| 1433. |
In a half wave voltage doubler circuit the input frequency is 50 Hz. The ripple frequency is |
| A. | 25 Hz |
| B. | 50 Hz |
| C. | 100 Hz |
| D. | 150 Hz |
| Answer» C. 100 Hz | |
| 1434. |
A differentiating amplifier has capacitor in the input path. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» B. False | |
| 1435. |
Pick the Odd one out |
| A. | MOSFET |
| B. | FET |
| C. | Planer transistor |
| D. | Unijunction transistor |
| Answer» E. | |
| 1436. |
In a BJT circuit a pnp transistor is replaced by npn transistor. To analyse the new circuit |
| A. | all calculations done earlier have to be repeated |
| B. | replace all calculated voltages by reverse values |
| C. | replace all calculated currents by reverse values |
| D. | replace all calculated voltages and currents by reverse values |
| Answer» E. | |
| 1437. |
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 | |
| 1438. |
A junction Field Effect Transistor can operate in |
| A. | depletion mode only |
| B. | enhancement mode only |
| C. | depletion and enhancement modes |
| D. | neither depletion nor enhancement modes |
| Answer» B. enhancement mode only | |
| 1439. |
In a biased limiter the clipping level can be adjusted by adjusting the voltage of battery. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» B. False | |
| 1440. |
For maximum unclipped output from a CE amplifier, the Q point should be |
| A. | at the centre of dc load line |
| B. | at the centre of ac load line |
| C. | at the centre of collector current |
| D. | none of the above |
| Answer» C. at the centre of collector current | |
| 1441. |
If the differential voltage gain and the common mode voltage gain of a differential amplifier are 48 dB and 2 dB respectively, then its common mode rejection ratio is |
| A. | 23 dB |
| B. | 25 dB |
| C. | 46 dB |
| D. | 50 dB |
| Answer» D. 50 dB | |
| 1442. |
Which of the following circuit does not need a coupling capacitor? |
| A. | Resistance loaded |
| B. | Transformer coupled |
| C. | Impedance coupled |
| D. | Single tuned |
| Answer» C. Impedance coupled | |
| 1443. |
In a BJT amplifier the power gain from base to collector is 4000. The power gain in dB is |
| A. | 3.6 |
| B. | 36 |
| C. | 7.2 |
| D. | 72 |
| Answer» C. 7.2 | |
| 1444. |
The emitter bias largely depends on |
| A. | gain |
| B. | signal input |
| C. | IE |
| D. | none of the above |
| Answer» D. none of the above | |
| 1445. |
A logarithmic amplifier has diode in the feedback path. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» B. False | |
| 1446. |
Pick the odd-one out |
| A. | Hartley Oscillator |
| B. | Colpitt oscillator |
| C. | Clapp oscillator |
| D. | Weinbridge oscillator |
| Answer» E. | |
| 1447. |
A collector collects |
| A. | electrons from the base in case of N-P-N transistor |
| B. | electrons from the emitter in case P-N-P transistor |
| C. | holes from the base in case of N-P-N transistor |
| D. | holes from the base in case of P-N-P transistor |
| Answer» C. holes from the base in case of N-P-N transistor | |
| 1448. |
Low gain-bandwidth product of a JFET is due to |
| A. | reduced number of holes |
| B. | junction capacitive effects |
| C. | low degree of isolation between input and output |
| D. | all of the above |
| Answer» C. low degree of isolation between input and output | |
| 1449. |
In a bistable multivibrator, commutating capacitors are used to |
| A. | increase the base storage charge |
| B. | provide ac coupling |
| C. | increase the speed of response |
| D. | alter the frequency of the output |
| Answer» D. alter the frequency of the output | |
| 1450. |
In figure, D1 turns on when |
| A. | vi is more than V1 |
| B. | vi is less than V1 |
| C. | vi is between V1 and V2 |
| D. | none of the above |
| Answer» B. vi is less than V1 | |