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MCQOPTIONS
This section includes 9294 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 2351. |
In full wave rectification, if the input frequency is 50 Hz, then frequency at the output of filter is |
| A. | 50 Hz |
| B. | 0 Hz |
| C. | 100 Hz |
| D. | 75 Hz |
| Answer» C. 100 Hz | |
| 2352. |
The circuit in the given figure is |
| A. | low pass filter |
| B. | high pass filter |
| C. | band Pass filter |
| D. | band reject filter |
| Answer» B. high pass filter | |
| 2353. |
The turn ratio of a transformer is 20:1, if a load of 10Ω is connected across the secondary, what will be the effective resistance seen looking into the Primary? |
| A. | 2 kΩ |
| B. | 4 kΩ |
| C. | 8 kΩ |
| D. | 32 kΩ |
| Answer» C. 8 kΩ | |
| 2354. |
If the Q of a single stage single tuned amplifier is doubled, the bandwidth will |
| A. | remain the same |
| B. | become half |
| C. | become double |
| D. | become four times |
| Answer» C. become double | |
| 2355. |
In a CE amplifier circuit the ac voltage between emitter and ground |
| A. | is very high |
| B. | may be high or low |
| C. | is zero |
| D. | depends on circuit configuration |
| Answer» D. depends on circuit configuration | |
| 2356. |
A full wave rectifier circuit using centre tapped transformer and a bridge rectifier are fed at 100 V, 50 Hz. The frequencies of outputs in these two rectifiers are |
| A. | 100 Hz each |
| B. | 50 Hz each |
| C. | 100 Hz and 50 Hz |
| D. | 50 Hz and 100 Hz |
| Answer» B. 50 Hz each | |
| 2357. |
When the ac base voltage in a CE amplifier circuit is too high, the ac emitter current is |
| A. | zero |
| B. | constant |
| C. | alternating |
| D. | distorted |
| Answer» E. | |
| 2358. |
When load is coupled to class A amplifier through transformer, efficiency decreases. |
| A. | True |
| B. | False |
| Answer» C. | |
| 2359. |
The open loop gain of an actual op-amp is about 100. |
| A. | True |
| B. | False |
| Answer» C. | |
| 2360. |
Figure is a 24 Vr stabilized power supply. The zener is 24 V, 600 mW. The minimum zener current is 10 mA. Proper values R and maximum load current are |
| A. | 320 Ω, 10 mA |
| B. | 400 Ω, 15 mA |
| C. | 400 Ω, 10 mA |
| D. | 320 Ω, 15 mA |
| Answer» E. | |
| 2361. |
Thermal run away of a transistor occurs when |
| A. | heat dissipation from transistor is excessive |
| B. | transistor joints melt due to high temperature |
| C. | there is excessive leakage current due to temperature rise |
| D. | none of the above |
| Answer» D. none of the above | |
| 2362. |
JFET has __________ degree of isolation between input and output, and a __________ noise figure. |
| A. | low, low |
| B. | high, high |
| C. | low, high |
| D. | high, low |
| Answer» E. | |
| 2363. |
The advantage of FET over BJT is |
| A. | high input impedance |
| B. | lower noise |
| C. | no thermal runaway |
| D. | all of the above |
| Answer» E. | |
| 2364. |
The MOSFET is almost ideal as a switching device because |
| A. | it has linear characteristics |
| B. | it works progressively |
| C. | it consumes low power |
| D. | it has longer life |
| Answer» D. it has longer life | |
| 2365. |
The input and output signals for CE amplifier are always |
| A. | equal |
| B. | in phase |
| C. | out of phase |
| D. | complementary to each other |
| Answer» D. complementary to each other | |
| 2366. |
Harmonic distortion in CB amplifier may be least when the load resistance is |
| A. | negligible |
| B. | very low |
| C. | very high |
| D. | infinite |
| Answer» D. infinite | |
| 2367. |
In a CE amplifier circuit the emitter by pass capacitor is remove. The ac output voltage |
| A. | increases |
| B. | remains the same |
| C. | increases or decreases |
| D. | decreases |
| Answer» E. | |
| 2368. |
In a differential amplifier, CMRR can be improved by using an increased |
| A. | emitter resistance |
| B. | collector resistance |
| C. | power supply voltages |
| D. | source resistance |
| Answer» B. collector resistance | |
| 2369. |
The voltage gains of an amplifier without feedback and with negative feedback respectively are 100 and 20. The percentage of negative feedback ( ) would be |
| A. | 40% |
| B. | 5% |
| C. | 20% |
| D. | 80% |
| Answer» B. 5% | |
| 2370. |
If a common emitter amplifier with an emitter resistance RC has an overall transconductance gain of 1 m A/V, a voltage gain of - 4 and desensitivity of 50, then the value of the emitter resistance R would be |
| A. | 50 kΩ |
| B. | 0.98 kΩ |
| C. | 50 Ω |
| D. | 0.98 Ω |
| Answer» C. 50 Ω | |
| 2371. |
For high frequency response of a transistor amplifier, suitable model to use is |
| A. | Kelvin network |
| B. | Lattice network |
| C. | Hybrid |
| D. | <span class="symbol">p</span> |
| E. | T-network |
| Answer» D. <span class="symbol">p</span> | |
| 2372. |
For the circuit shown in the figure, the capacitor C is initially uncharged. At t = 0, the switch S is closed. The voltage Vc across the capacitor at t = 1 millisecond is (In the figure shown above, the op-amp is supplied with 15 V and the ground has been shown by the symbol) |
| A. | 0 V |
| B. | 6.3 V |
| C. | 9.45 volts |
| D. | 10 volts |
| Answer» E. | |
| 2373. |
In amplifiers, the parasitic oscillation result due to |
| A. | transistor inter junction capacitance |
| B. | push pull operator |
| C. | negative feedback |
| D. | poor inter-stage coupling |
| Answer» B. push pull operator | |
| 2374. |
A radio frequency choke permits an easy flow of __________ current and at the same time it offers a very impedance to __________ currents. |
| A. | A.C., low frequency |
| B. | A.C., high frequency |
| C. | D.C., low frequency |
| D. | D.C. high frequency |
| Answer» E. | |
| 2375. |
Assertion (A): In an op-amp the gain bandwidth product equals ffinityReason (R): The change in open loop gain of an amplifier has almost no effect on closed loop 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» C. A is correct R is wrong | |
| 2376. |
Lower chip area requirements of MOS is advantage in |
| A. | low power circuits |
| B. | high power circuits |
| C. | repetitive operation circuits |
| D. | large scale integration |
| Answer» E. | |
| 2377. |
A transistor with a = 0.98 then will be |
| A. | 49 |
| B. | 50 |
| C. | 47 |
| D. | 48 |
| Answer» B. 50 | |
| 2378. |
Power transistors are invariably provided with |
| A. | soldered connections |
| B. | heat sink |
| C. | metallic casing |
| D. | none of the above |
| Answer» C. metallic casing | |
| 2379. |
Assertion (A): The ac load line is different from dc load lineReason (R): The ac load resistance seen by collector and emitter is different from dc load 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 | |
| 2380. |
In a class C operation VCC = 40 V and VCE(sat) = 0.4 V. The efficiency is |
| A. | 90% |
| B. | 49.5% |
| C. | 1% |
| D. | 0.5% |
| Answer» B. 49.5% | |
| 2381. |
The circuit shown in figure will |
| A. | oscillate at 456 kHz |
| B. | oscillate at 228 kHz |
| C. | oscillate at microwave frequency |
| D. | not oscillate |
| Answer» E. | |
| 2382. |
The absolute values of pinch-off voltage and gate-source cut-off voltage are |
| A. | nearly zero |
| B. | complementary to each other |
| C. | never equal |
| D. | equal |
| Answer» E. | |
| 2383. |
In the case of the circuit shown in the figure, the collector current IC will be, if = 100, VBE = 0.7 V, ICO = 0.1 A at 20 C |
| A. | 2.26 mA |
| B. | 1.85 mA |
| C. | 0.357 mA |
| D. | 0.185 mA |
| Answer» B. 1.85 mA | |
| 2384. |
A three-section RC phase shift oscillator has R = 10K ohms and C = 0.001 F. The frequency of oscillations is |
| A. | 1.1 kHz |
| B. | 2.5 kHz |
| C. | 3.3 kHz |
| D. | 6.5 kHz |
| Answer» E. | |
| 2385. |
Barkhausen criterion is 1 + Av = 0. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 2386. |
The circuit of figure is |
| A. | positive clipper |
| B. | negative clipper |
| C. | combination clipper |
| D. | either (a) or (b) |
| Answer» D. either (a) or (b) | |
| 2387. |
A Darlington pair has = 300. If RE = 1 k&ohm; and RL = 100 &ohm;, the input impedance at the base is approximately |
| A. | 300 k ohm |
| B. | 3 k ohm |
| C. | 100 k ohm |
| D. | 30 k ohm |
| Answer» C. 100 k ohm | |
| 2388. |
Assertion (A): Electric coupling, magnetic coupling and ground loop can cause unwanted high frequency oscillations.Reason (R): Hartley oscillator uses a tapped inductor |
| 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 | |
| 2389. |
In figure VCE (sat) = 0.1 V. Then IC (sat) = |
| A. | 10 mA |
| B. | 20 mA |
| C. | 30 mA |
| D. | 40 mA |
| Answer» C. 30 mA | |
| 2390. |
If the thermal resistance of a transistor is lower it means |
| A. | higher junction temperature |
| B. | lower junction temperature |
| C. | higher or lower junction temperature depending on circuit conditions |
| D. | higher or lower junction temperature depending on transistor |
| Answer» C. higher or lower junction temperature depending on circuit conditions | |
| 2391. |
The voltage gain of which transistor configuration is less than unity? |
| A. | CB |
| B. | CE |
| C. | CC |
| D. | None |
| Answer» D. None | |
| 2392. |
Linear transistor circuits always operate in |
| A. | saturation region |
| B. | cut off region |
| C. | active region |
| D. | passive region |
| Answer» D. passive region | |
| 2393. |
A push pull amplifier balance out |
| A. | odd harmonics |
| B. | even harmonics |
| C. | both odd as well as even harmonics |
| D. | neither odd nor even harmonics |
| Answer» B. even harmonics | |
| 2394. |
In a half wave rectifier, Vrms is |
| A. | <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/331-496-1.png"> |
| B. | <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/331-496-2.png"> |
| C. | <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/331-496-3.png"> |
| D. | None of these |
| Answer» B. <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/331-496-2.png"> | |
| 2395. |
In a full wave rectifier circuit using centre tapped transformer, the peak voltage across half the secondary winding is 40 V. If diodes are ideal, the average output voltage is |
| A. | 40 V |
| B. | 25.5 V |
| C. | 20 V |
| D. | 2.55 V |
| Answer» C. 20 V | |
| 2396. |
In a bipolar transistor at room temperature if the emitter current is doubled the voltage across its base emitter junction |
| A. | doubles |
| B. | halves |
| C. | increase by about 20 mV |
| D. | decrease by about 20 mV |
| Answer» C. increase by about 20 mV | |
| 2397. |
In the circuit of figure diode will conduct |
| A. | from 90 to 180 in the positive half cycle |
| B. | from 30 to 180 in the positive half cycle |
| C. | from 50 to 160 in the positive half cycle |
| D. | from 30 to 150 in the positive half cycle |
| Answer» E. | |
| 2398. |
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 | |
| 2399. |
The most widely used diode rectifier circuit is |
| A. | half wave |
| B. | full wave with centre tapped transformer |
| C. | bridge |
| D. | either (a) or (b) |
| Answer» D. either (a) or (b) | |
| 2400. |
The main advantage of a crystal oscillator |
| A. | can oscillate any frequency |
| B. | gives a high output voltage |
| C. | frequency of oscillation is almost constant |
| D. | can operates at a low dc voltage |
| Answer» D. can operates at a low dc voltage | |