MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 1136 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics & Communication Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 501. |
In a crystal |
| A. | the frequencies of series and parallel resonance are equal |
| B. | the frequency of series resonance is more than frequency of parallel resonance |
| C. | the frequency of parallel resonance is more than frequency of series resonance |
| D. | None of the above |
| Answer» D. None of the above | |
| 502. |
In a transistor, current ICBO flow when |
| A. | some D.C. voltage is applied in the reverse direction to the emitter junction with the collector open circuit |
| B. | some D.C. voltage is applied in the forward direction to the collector junction with the emitter open circuit |
| C. | some D.C. voltage is applied in the reverse direction to the collector junction with the emitter open circuited |
| D. | some D.C. voltage is applied in the forward direction to the emitter junction with the collector open circuited |
| Answer» D. some D.C. voltage is applied in the forward direction to the emitter junction with the collector open circuited | |
| 503. |
When a CE transistor is cut off |
| A. | voltage across collector reduces to zero |
| B. | voltage across collector is maximum |
| C. | maximum collector current flows |
| D. | maximum voltage appears across the load resistance |
| Answer» C. maximum collector current flows | |
| 504. |
A voltage tripler circuit uses |
| A. | 2 diodes and 2 capacitors |
| B. | 3 diodes and 3 capacitors |
| C. | 2 diodes and 3 capacitors |
| D. | 3 diodes and 2 capacitors |
| Answer» C. 2 diodes and 3 capacitors | |
| 505. |
The feedback resistance rd in small signal model of MOSFET is of the order of |
| A. | 1000 MΩ |
| B. | 1 MΩ |
| C. | 1 KΩ |
| D. | 100 Ω |
| Answer» B. 1 MŒ© | |
| 506. |
A class B amplifier is biased just at cutoffhas a high theoretical efficiency of 78.5% because its quiescent current is lowis biased at midpoint of load line Of the above statements |
| A. | 2 and 3 are correct |
| B. | 1 alone is correct |
| C. | 1 and 2 are correct |
| D. | 2 alone is correct |
| Answer» E. | |
| 507. |
Which of the following is not the main characteristic of a FET? |
| A. | Drain resistance |
| B. | Forward transconductance |
| C. | Temperature stability |
| D. | Amplification factor |
| Answer» D. Amplification factor | |
| 508. |
A buffer amplifier should have |
| A. | high output impedance and high input impedance |
| B. | high output impedance and low input impedance |
| C. | low output impedance an low input impedance |
| D. | low output impedance and high input impedance |
| Answer» E. | |
| 509. |
Aperture circuit produces __________ in sample hold circuit. |
| A. | the total sampling time |
| B. | delay between the instance at which hold command is initiated and the instance at which O/P starts tracking I/P |
| C. | the time taken by O/P to settle within the specified 1% error band, that of the I/P |
| D. | time required by holding capacitor to reach upto the level close to input |
| Answer» C. the time taken by O/P to settle within the specified 1% error band, that of the I/P | |
| 510. |
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. | |
| 511. |
A BJT amplifier has a power gain of 0.5 from source to base. The power gain in dB is |
| A. | -0.3 dB |
| B. | -3 dB |
| C. | -6 dB |
| D. | -10 dB |
| Answer» C. -6 dB | |
| 512. |
Voltage VL in the circuit when Vs < 0 where D is an ideal diode. (Take R1 = Rs = RL = 1 Ω) |
| A. | 0 |
| B. | 1 |
| C. | 1.5 |
| D. | cannot find |
| Answer» B. 1 | |
| 513. |
In a base driver amplifier the voltage gain is the ratio of |
| A. | ac collector voltage to ac base voltage |
| B. | ac emitter voltage to ac base voltage |
| C. | ac collector voltage to ac emitter voltage |
| D. | ac base voltage to ac emitter voltage |
| Answer» B. ac emitter voltage to ac base voltage | |
| 514. |
For high frequencies a capacitor like |
| A. | an open circuit |
| B. | a short circuit |
| C. | either open circuit or short circuit |
| D. | none of the above |
| Answer» C. either open circuit or short circuit | |
| 515. |
In calculating output impedance of an amplifier the source is replaced by an open circuit. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 516. |
A voltage doubler circuit uses |
| A. | two diodes |
| B. | two capacitors |
| C. | two diodes and two capacitors |
| D. | none of the above |
| Answer» D. none of the above | |
| 517. |
In a voltage regulator circuit using zener diode the load voltage is nearly constant only if |
| A. | zener current is very small |
| B. | zener current is very large |
| C. | zener current is neither small nor large |
| D. | None of the above |
| Answer» B. zener current is very large | |
| 518. |
For an amplifier the input output signals are shown in figure. The class of amplifier is |
| A. | A |
| B. | AB |
| C. | B |
| D. | C |
| Answer» E. | |
| 519. |
Which configuration is suitable for impedance matching? |
| A. | CB |
| B. | CE |
| C. | CC |
| D. | CB and CE |
| Answer» D. CB and CE | |
| 520. |
For transistor 2 N 338 the manufacturer specifies Pmax = 100 mW at 250°C free air temperature and maximum junction temperature of 125°C. Its thermal resistance is |
| A. | 10° C/W |
| B. | 100° C/W |
| C. | 1000° C/W |
| D. | 5000° C/W |
| Answer» D. 5000¬∞ C/W | |
| 521. |
The main drawback in the performance of shunt peaked wide band amplifier is |
| A. | two low gain at low frequency |
| B. | poor phase response |
| C. | reduce frequency at middle frequency |
| D. | that the maximum gain of the stage is small |
| Answer» C. reduce frequency at middle frequency | |
| 522. |
In a class C power amplifier |
| A. | resonant frequency of tuned circuit is equal to fundamental frequency of pulsed waveform |
| B. | resonant frequency of tuned circuit is half the fundamental frequency of pulsed waveform |
| C. | resonant frequency of tuned circuit has no relation to the fundamental frequency of pulsed waveform |
| D. | either (b) or (c) |
| Answer» B. resonant frequency of tuned circuit is half the fundamental frequency of pulsed waveform | |
| 523. |
In a CB amplifier the maximum efficiency could be |
| A. | 0.99 |
| B. | 0.85 |
| C. | 0.5 |
| D. | 0.25 |
| Answer» E. | |
| 524. |
In a bridge rectifier circuit the rms value of input ac voltage is 10 V. The PIV across each diode is |
| A. | 7.07 V |
| B. | 14.14 V |
| C. | 10 V |
| D. | 28.28 V |
| Answer» C. 10 V | |
| 525. |
In an amplifier the stray capacitances assume impedance at low frequencies |
| A. | 1 |
| B. | |
| Answer» C. | |
| 526. |
In order to rectify sinusoidal signals of millivolt range (< 0.6 V) |
| A. | bridge rectifier using diodes can be employed |
| B. | full wave diode rectifier can be used |
| C. | a diode is to be inserted in the feedback loop of an op-amp |
| D. | a diode is to be inserted in the I/P of an op-amp |
| Answer» D. a diode is to be inserted in the I/P of an op-amp | |
| 527. |
In a transistor with normal bias |
| A. | the emitter junction has a low resistance |
| B. | the emitter junction has a very high resistance |
| C. | the emitter junction supplies majority carries into the base region |
| D. | none of the above |
| Answer» B. the emitter junction has a very high resistance | |
| 528. |
In a CE amplifier circuit the dc voltage between emitter and ground |
| A. | is always zero |
| B. | cannot be zero |
| C. | may or may not be zero |
| D. | is negative |
| Answer» C. may or may not be zero | |
| 529. |
Cross-over distortion behaviour is a characteristic of |
| A. | class A output stage |
| B. | class B output stage |
| C. | class AB output stage |
| D. | common base output stage |
| Answer» C. class AB output stage | |
| 530. |
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 | |
| 531. |
A FET is a better clapper than a BJT because it has |
| A. | lower off-set voltage |
| B. | higher series ON resistance |
| C. | lower input current |
| D. | higher input impedance |
| Answer» B. higher series ON resistance | |
| 532. |
In figure |
| A. | the collector currents of T1 and T2 are equal |
| B. | the collector current of T1 is more than that of T2 |
| C. | the collector current of T1 is double that of T2 |
| D. | the collector currents of T2 is more than that of T1 |
| Answer» B. the collector current of T1 is more than that of T2 | |
| 533. |
In an inverting amplifier using op-amp the current input to the inverting terminal |
| A. | is equal to the current through feedback resistance |
| B. | is less than the current through feedback resistance |
| C. | is more than the current through feedback resistance |
| D. | may be equal to, less or more than current through feedback resistance |
| Answer» B. is less than the current through feedback resistance | |
| 534. |
A complementary symmetry amplifier has |
| A. | 1 P-N-P and 1 N-P-N transistor |
| B. | 2 P-N-P transistor |
| C. | 2 N-P-N transistor |
| D. | 2 P-channel FETs |
| Answer» B. 2 P-N-P transistor | |
| 535. |
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 | |
| 536. |
In the case of the circuit shown in the figure Vio = 10 mV dc maximum, the maximum possible output offset voltage Voo caused by the input offset voltage Vio with respect to ground is |
| A. | 60 mV dc |
| B. | 110 mV dc |
| C. | 130 mV dc |
| D. | 150 mV dc |
| Answer» D. 150 mV dc | |
| 537. |
In figure it is desired that output wave is symmetrical. Then |
| A. | both diodes should be similar and |V1| = |V2| |
| B. | both diodes should be similar |
| C. | |V1| = |V2| |
| D. | either (a) or (b) |
| Answer» B. both diodes should be similar | |
| 538. |
Assertion (A): A self bias circuit is the most commonly used bias circuit for bipolar junction transistorsReason (R): A self bias circuit limits the increase in collector or emitter current due to change in junction temperature. |
| 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 | |
| 539. |
Circuit shown in the figure is |
| A. | astable multivibrator |
| B. | monostable multivibrator |
| C. | VCO |
| D. | ramp Generator |
| Answer» B. monostable multivibrator | |
| 540. |
Which of the following op-amp circuits has zero resistance in the feedback path? |
| A. | Inverting amplifier |
| B. | Summing amplifier |
| C. | Source follower |
| D. | Integrating amplifier |
| Answer» D. Integrating amplifier | |
| 541. |
The frequency response of an ideal tuned amplifier should be as represented in figure by |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 542. |
The open loop gain of an amplifier is 50 but likely to decrease by 20% due to various factors. If negative feedback with β = 0.1 is used, the change in gain will be about |
| A. | 0.2 |
| B. | 0.02 |
| C. | 0.005 |
| D. | 0.0005 |
| Answer» D. 0.0005 | |
| 543. |
In following figure, what will be R1 and R2 for maximum symmetrical swing if VCSat ≈ 0. Given that RE = 200 Ω, RC = 400 Ω, VCC = 20 V, β = 99 |
| A. | 6 k |
| B. | 3 k, 6 k |
| C. | 9.9 k, 2.4 k |
| D. | 2.4 k, 9.9 k |
| Answer» E. | |
| 544. |
The purpose of connecting a coupling capacitor in the output circuit of an amplifier is |
| A. | to increase voltage gain |
| B. | to increase collector current |
| C. | to block dc collector voltage |
| D. | all of the above |
| Answer» D. all of the above | |
| 545. |
In a single stage differential amplifier, the output offset voltage is mainly dependent on the mismatch of |
| A. | VBE, IB and β |
| B. | VBE and IB |
| C. | IB and β |
| D. | VBE and β |
| Answer» C. IB and Œ≤ | |
| 546. |
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 | |
| 547. |
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 | |
| 548. |
An oscillator requires an amplifier |
| A. | with negative feedback |
| B. | with positive feedback |
| C. | with either positive or negative feedback |
| D. | none of the above |
| Answer» C. with either positive or negative feedback | |
| 549. |
In logarithmic amplifiers, output voltage is equal to |
| A. | K.log10 (input voltage) |
| B. | K.loge (input voltage) |
| C. | input voltage |
| Answer» C. input voltage | |
| 550. |
The purpose of impedance matching in an amplifier circuit is to achieve |
| A. | high efficiency |
| B. | reduce distortion |
| C. | maximum power transfer |
| D. | none of the above |
| Answer» D. none of the above | |