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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.
| 751. |
A Darlington pair consist of |
| A. | two CB amplifiers |
| B. | two CC amplifiers |
| C. | two cascaded CC amplifiers |
| D. | two cascaded CE amplifiers |
| Answer» D. two cascaded CE amplifiers | |
| 752. |
The most common method for biasing a JFET is |
| A. | reverse bias |
| B. | self bias |
| C. | voltage divider bias |
| D. | none of the above |
| Answer» C. voltage divider bias | |
| 753. |
A Darlington pair is used for |
| A. | low distortion |
| B. | high frequency range |
| C. | high power gain |
| D. | high current gain |
| Answer» E. | |
| 754. |
In a class C operation |
| A. | VCC is much larger than VCE(sat) |
| B. | VCC is much smaller than VCE(sat) |
| C. | VCC and VCE(sat) are nearly equal |
| D. | none of the above |
| Answer» B. VCC is much smaller than VCE(sat) | |
| 755. |
In a series regulated power supply circuit, the voltage gain Av, of the 'pass' transistor satisfies the condition |
| A. | Av ‚Üí ‚àû |
| B. | 1 << Av < ‚àû |
| C. | Av ≈ 1 |
| D. | Av << 1 |
| Answer» D. Av << 1 | |
| 756. |
A half wave diode rectifier uses a diode having forward resistance of 50 ohms. The load resistance is also 50 ohms. Then the voltage regulation is |
| A. | 0.2 |
| B. | 0.5 |
| C. | 1 |
| D. | 2 |
| Answer» D. 2 | |
| 757. |
Whenever a JFET operates above pinch-off voltage |
| A. | depletion regions become smaller |
| B. | drain current increase steeply |
| C. | drain current starts decreasing |
| D. | drain current remains nearly constant |
| Answer» E. | |
| 758. |
Positive feedback is mainly used in |
| A. | oscillators |
| B. | thyristors |
| C. | voltage regulators |
| D. | both (a) and (b) |
| Answer» E. | |
| 759. |
The basic amplifier in Weinbridge oscillator consists of |
| A. | CE stage followed by CE |
| B. | CE stage followed by CB |
| C. | CB stage followed by CE |
| D. | CC stage followed by CE |
| Answer» B. CE stage followed by CB | |
| 760. |
In a CE amplifier circuit |
| A. | Q point must lie on both dc and ac load lines |
| B. | Q point lies on dc load line |
| C. | Q point lies on ac load line |
| D. | Q point lies may or may not lie on both dc and ac load lines |
| Answer» B. Q point lies on dc load line | |
| 761. |
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 output signal-to-noise ratio is |
| A. | 100 |
| B. | 50 |
| C. | 10 |
| D. | 5 |
| Answer» C. 10 | |
| 762. |
A cascade amplifier stage is equivalent to |
| A. | common emitter stage followed by a common base stage |
| B. | common base stage followed by an emitter follower |
| C. | an emitter follower stage followed by a common base stage |
| D. | a common base stage followed by a common emitter stage |
| Answer» B. common base stage followed by an emitter follower | |
| 763. |
In figure the dc load line will meet the y and x axis respectively at |
| A. | 20 mA and 30 V |
| B. | 15 mA and 20 V |
| C. | 25 mA and 40 V |
| D. | 10 mA and 20 V |
| Answer» B. 15 mA and 20 V | |
| 764. |
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 | |
| 765. |
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. | |
| 766. |
In figure, IC ≈ |
| A. | I1 |
| B. | IB |
| C. | 0.5 I1 |
| D. | 0.5 IB |
| Answer» B. IB | |
| 767. |
For the circuit shown in figure low cut-off frequency is |
| A. | 1.59 Hz |
| B. | 159 Hz |
| C. | 1.59 kHz |
| D. | 1.59 MHz |
| Answer» B. 159 Hz | |
| 768. |
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. | |
| 769. |
A Wien bridge is suitable for |
| A. | audio frequencies only |
| B. | radio frequencies only |
| C. | both audio and radio frequencies |
| D. | very low frequencies only |
| Answer» B. radio frequencies only | |
| 770. |
The purpose of providing groundings rings with MOSFET is to |
| A. | avoid any stray voltage at the gate that may destroy SiO2 layer |
| B. | protect against any descaling |
| C. | ground all eddy currents |
| D. | protect against any physical injury |
| Answer» B. protect against any descaling | |
| 771. |
A multivibrator generates |
| A. | sinusoidal waveforms |
| B. | non-sinusoidal waveforms |
| C. | both (a) and (b) |
| D. | none of the above |
| Answer» B. non-sinusoidal waveforms | |
| 772. |
Find resistance RB to bring transistor to threshold of saturation VCB = 0, VBE = 0.7 V, a = 0.96 |
| A. | 1.5 kΩ |
| B. | 15 kΩ |
| C. | 10 kΩ |
| D. | 1 kΩ |
| Answer» B. 15 kŒ© | |
| 773. |
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 | |
| 774. |
The slew rate of an ideal op-amp is |
| A. | very slow |
| B. | slow |
| C. | fast |
| D. | infinitely fast |
| Answer» E. | |
| 775. |
Class A amplifiers are preferred when |
| A. | minimum distortion is required |
| B. | maximum voltage gain is required |
| C. | output signal is desired in phase with input signal |
| D. | signal having A.C. superimposed on D.C. are to be amplified |
| Answer» B. maximum voltage gain is required | |
| 776. |
A 741 type op-amp has a gain bandwidth product of 1 MHz. A non-inverting amplifier using this op-amp and having a voltage gain of 20 dB will exhibit a -3dB bandwidth of |
| A. | 50 kHz |
| B. | 100 kHz |
| Answer» C. | |
| 777. |
As compared to full wave rectifier, a half wave rectifier |
| A. | has higher ripple factor |
| B. | has lower ripple factor |
| C. | may have higher or lower ripple factor |
| D. | has same ripple factor |
| Answer» B. has lower ripple factor | |
| 778. |
The ideal characteristics of a stabilizer is |
| A. | constant output voltage with low internal resistance |
| B. | constant output current with low internal resistance |
| C. | constant output voltage with high internal resistance |
| D. | constant internal resistance and constant output current |
| Answer» B. constant output current with low internal resistance | |
| 779. |
The bandwidth of an amplifier can be reduced by |
| A. | miller effect compensation |
| B. | pole zero compensation |
| C. | dominant pole compensation |
| D. | lead compensation |
| Answer» D. lead compensation | |
| 780. |
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 | |
| 781. |
Which circuit is called emitter follower? |
| A. | CC |
| B. | CE |
| C. | CB |
| D. | Both (a) and (b) |
| Answer» B. CE | |
| 782. |
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 | |
| 783. |
In the amplifier circuit figure the quiescent point voltage and current are |
| A. | 12 V, 5 mA |
| B. | 12 V, 2 mA |
| C. | 10 V, 2 mA |
| D. | 10 V, 5 mA |
| Answer» D. 10 V, 5 mA | |
| 784. |
The circuit consisting of two transistor connected in series with the d.c. supply voltage is called |
| A. | push pull |
| B. | differential pair |
| C. | stacked V+ |
| D. | complementary symmetry |
| Answer» D. complementary symmetry | |
| 785. |
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 | |
| 786. |
As per miller theorem the circuit of figure (1) can be replaced by that in figure (2) If V1/V2 = K, then Y1 and Y2 are equal to |
| A. | Y(1 - K) each |
| B. | each |
| C. | Y1 = Y(1 - K) and Y2 = |
| D. | Y1 = and Y2 = (1 - K) |
| Answer» D. Y1 = and Y2 = (1 - K) | |
| 787. |
In CE approximation, the upper end of d.c. load line is called the __________ point and the lower end is the __________ point. |
| A. | Q, base |
| B. | base, Q |
| C. | saturation, cut off |
| D. | cut off, saturation |
| Answer» D. cut off, saturation | |
| 788. |
Calculate the O/P voltage of a non-inverting constant gain multiplier with R1 = 100 kΩ, Rf= 600 kΩ, V1 = 2 volt, then O/P voltage Vo of non inverting op-amp is given by |
| A. | 16 V |
| B. | 14 V |
| C. | 20 V |
| D. | 15 V |
| Answer» C. 20 V | |
| 789. |
A bipolar transistor is a __________ controlled devices whereas a FET is a __________ controlled devices. |
| A. | current, voltage |
| B. | current, current |
| C. | voltage, current |
| D. | voltage, voltage |
| Answer» B. current, current | |
| 790. |
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 | |
| 791. |
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 | |
| 792. |
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 | |
| 793. |
In every practical oscillator, the loop gain is slightly larger than unity and the amplitude of the oscillations is limited by the |
| A. | magnitude of the loop gain |
| B. | onset if non-linearity |
| C. | magnitude of gain of the amplifier |
| D. | feedback transmission factor |
| Answer» C. magnitude of gain of the amplifier | |
| 794. |
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 | |
| 795. |
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 | |
| 796. |
Oscillator with best frequency stability is |
| A. | Crystal oscillator |
| B. | Phase shift oscillator |
| C. | Clapp oscillator |
| D. | Hartley oscillator |
| Answer» B. Phase shift oscillator | |
| 797. |
In a common emitter circuit all voltages are measured with respect to |
| A. | base |
| B. | emitter |
| C. | collector |
| D. | base or collector |
| Answer» C. collector | |
| 798. |
The re model equivalent circuit shown in figure is for |
| A. | CE amplifier |
| B. | CC amplifier |
| C. | CB amplifier |
| D. | None of the above |
| Answer» D. None of the above | |
| 799. |
The circuit shown in figure will act as |
| A. | differentiator |
| B. | adder |
| C. | clipper |
| D. | clamper |
| Answer» D. clamper | |
| 800. |
For a transistor if adc = 0.98 and emitter current IE is 2 mA, then collector current will be |
| A. | 0.44 mA |
| B. | 0.88 mA |
| C. | 1.96 mA |
| D. | 3.32 mA |
| Answer» C. 1.96 mA | |