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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.
| 2051. |
A TRIAC is a semiconductor device which acts as a |
| A. | 2 terminal unidirectional switch |
| B. | 2 terminal bidirectional switch |
| C. | 3 terminal bidirectional switch |
| D. | 4 terminal multidirectional switch |
| Answer» D. 4 terminal multidirectional switch | |
| 2052. |
A dc amplifier can operate |
| A. | at zero frequency |
| B. | only at low frequency |
| C. | only at high frequencies |
| D. | both at low and high frequencies |
| Answer» B. only at low frequency | |
| 2053. |
In each of circuits below, indicate which diode is conducting? |
| A. | Figure A |
| B. | Figure B |
| C. | Figure C |
| D. | All the three |
| Answer» E. | |
| 2054. |
The oscillator shown in figure is a |
| A. | Colpitt's oscillator |
| B. | Hartley oscillator |
| C. | Tuned emitter oscillator |
| D. | Clapp oscillator |
| Answer» B. Hartley oscillator | |
| 2055. |
In which configuration does output ac voltage appear between emitter and ground? |
| A. | CE |
| B. | CB |
| C. | CC |
| D. | Both CE and CB |
| Answer» D. Both CE and CB | |
| 2056. |
Figure represents a |
| A. | JFET shunt switching circuit |
| B. | JFET series switching circuit |
| C. | JFET analog switch |
| D. | multiplexing |
| Answer» C. JFET analog switch | |
| 2057. |
At high frequencies the output circuit of transistor amplifier reduces to |
| A. | a lead network |
| B. | a lag network |
| C. | either (a) or (b) |
| D. | neither (a) nor (b) |
| Answer» C. either (a) or (b) | |
| 2058. |
The noise figure is |
| A. | 3 dB |
| B. | 6 dB |
| C. | 6.6 dB |
| D. | 12 dB |
| Answer» B. 6 dB | |
| 2059. |
A Darlington pair is used for |
| A. | low distortion |
| B. | high frequency range |
| C. | high power gain |
| D. | high current gain |
| Answer» E. | |
| 2060. |
In a shunt-shunt negative feedback amplifier, as compared to the basic amplifier |
| A. | both input and output impedances, decrease |
| B. | input impedance decreases but output impedance increase |
| C. | I/P impedance increases but O/P impedance decreases |
| D. | both input and O/P impedance increases |
| Answer» C. I/P impedance increases but O/P impedance decreases | |
| 2061. |
In rectifiers the use of RC filters is recommended when |
| A. | load current is high |
| B. | load current is small |
| C. | load current is neither high nor small |
| D. | either (a) or (c) |
| Answer» C. load current is neither high nor small | |
| 2062. |
The coupling capacitor mainly affects |
| A. | bandwidth |
| B. | lower cut-off frequency |
| C. | higher cut-off frequency |
| D. | both lower as well as higher cut-off frequency |
| Answer» C. higher cut-off frequency | |
| 2063. |
Transformer coupling in transistor amplifier circuits provides high efficiency, because |
| A. | d.c. resistance is low |
| B. | collector voltage is stepped up |
| C. | flux linkages are incomplete |
| D. | all of the above |
| Answer» B. collector voltage is stepped up | |
| 2064. |
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. | |
| 2065. |
If f is more than funity the gain of op-amp becomes less than 1. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 2066. |
A 1 ms pulse can be stretched to 1 sec pulse by using |
| A. | an astable multivibrator |
| B. | a monostable multivibrator |
| C. | a bistable multivibrator |
| D. | a Schmitt trigger circuit |
| Answer» C. a bistable multivibrator | |
| 2067. |
Most of the transistor data sheets specify the power rating for an ambient temperature of |
| A. | 10 C |
| B. | 25 C |
| C. | 50 C |
| D. | 75 C |
| Answer» C. 50 C | |
| 2068. |
In a N-P-N transistor the function of the emitter is |
| A. | to emit or inject holes into the collector |
| B. | to emit or inject electrons into the collector |
| C. | to emit or inject electrons into the base |
| D. | to emit or inject holes into the base |
| Answer» D. to emit or inject holes into the base | |
| 2069. |
In figure vi is a sinusoidal wave. Which of the following best describes the output v0? |
| A. | <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/319-265-1.png"> |
| B. | <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/319-265-2.png"> |
| C. | <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/319-265-3.png"> |
| D. | <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/319-265-4.png"> |
| Answer» C. <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/319-265-3.png"> | |
| 2070. |
The early effect in BJT is caused by |
| A. | fast turn on |
| B. | fast turn off |
| C. | large collector base reverse bias |
| D. | large emitter base forward bias |
| Answer» D. large emitter base forward bias | |
| 2071. |
The static characteristic of an adequately forward biased p-n junction is a straight line if the plot is of |
| A. | log I vs log V |
| B. | log I vs V |
| C. | I vs log V |
| D. | I vs V |
| Answer» C. I vs log V | |
| 2072. |
The main use of JFET with a |
| A. | frequency mixer |
| B. | source follower |
| C. | voltage doubler |
| D. | trigger |
| Answer» C. voltage doubler | |
| 2073. |
Figure represents |
| A. | Integrator |
| B. | Differentiator |
| C. | High Pass Filter |
| D. | Band Pass Filter |
| Answer» B. Differentiator | |
| 2074. |
Assertion (A): A dc stabilizer has constant output voltage irrespective of variations in input voltage and load currentReason (R): A dc series regulator uses a zener diode across the load to stabilize the output voltage. |
| 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 | |
| 2075. |
In op-amp integrating amplifier the input is feed to |
| A. | inverting input |
| B. | non-inverting input |
| C. | both inverting and non-inverting input |
| D. | either inverting or non-inverting input |
| Answer» B. non-inverting input | |
| 2076. |
Which of the following circuits can operate class AB for audio power output? |
| A. | Emitter follower |
| B. | Push pull |
| C. | Cascade |
| D. | Darlington pair |
| Answer» E. | |
| 2077. |
In a P-N-P transistor, with normal bias |
| A. | the collector junction has negligible resistance |
| B. | only holes cross the collector junction |
| C. | the collector-base junction is reverse biased and the emitter base junction is forward biased |
| D. | only majority carriers cross the collector junction |
| Answer» D. only majority carriers cross the collector junction | |
| 2078. |
Two transistors have same value of a but different gain (G) bandwidth (B) product. The transistors have similar geometry. However one of them is germanium and the other is silicon. The transistor with lower GB product |
| A. | is germanium |
| B. | is silicon |
| C. | may be either of two |
| D. | cannot be identified on the basis of above data |
| Answer» C. may be either of two | |
| 2079. |
If Rs is the sources resistance, the O/P resistance of an emitter follower using the simplified hybrid model would be |
| A. | <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/338-591-1.png"> |
| B. | <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/338-591-2.png"> |
| C. | <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/338-591-3.png"> |
| D. | <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/338-591-4.png"> |
| Answer» B. <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/338-591-2.png"> | |
| 2080. |
A D.C. amplifier amplify |
| A. | D.C. only |
| B. | A.C. only |
| C. | both A.C. and D.C. |
| D. | none of the above. |
| Answer» B. A.C. only | |
| 2081. |
In common base amplifier the current gain is less than one, but the voltage gain may be anywhere from |
| A. | 0.5 to 1 |
| B. | 1 to 5 |
| C. | 5 to 10 |
| D. | 50 to 2000 |
| Answer» E. | |
| 2082. |
Which of the following can be used to isolate a low impedance from a high impedance source? |
| A. | Emitter follower |
| B. | <span class="symbol">p</span> |
| C. | filter |
| D. | Darlington pair |
| E. | Any of the above |
| Answer» B. <span class="symbol">p</span> | |
| 2083. |
A class C amplifier uses |
| A. | high Q tuned circuit |
| B. | low Q tuned circuit |
| C. | untuned circuit |
| D. | either (b) or (c) |
| Answer» B. low Q tuned circuit | |
| 2084. |
The properties of FETs resemble closely to |
| A. | UJT |
| B. | current transformer |
| C. | thyristor |
| D. | thermionic valves |
| Answer» E. | |
| 2085. |
Which distortion is least objectionable in case of audio amplifiers? |
| A. | Phase distortion |
| B. | Frequency distortion |
| C. | Harmonic distortion |
| D. | Inter-modulation distortion |
| Answer» B. Frequency distortion | |
| 2086. |
A transistor is said to be in a quiescent state when |
| A. | the amplitude of input and output signal is equal |
| B. | the phase of input and output signal is identical |
| C. | no signal is applied to the input |
| D. | the transistor is unbiased |
| Answer» D. the transistor is unbiased | |
| 2087. |
According to Barkhausen criteria in order to sustain the oscillations |
| A. | loop gain of the circuit must be negligible |
| B. | loop gain of the circuit must be equal to unity |
| C. | the phase shift around the circuit must be 180 |
| D. | none of the above |
| Answer» C. the phase shift around the circuit must be 180 | |
| 2088. |
A Wien bridge oscillator uses |
| A. | negative feedback |
| B. | positive feedback |
| C. | both negative and positive feedback |
| D. | none of the above |
| Answer» D. none of the above | |
| 2089. |
In the above case, what will be the value of capacitor to obtain 100 kHz frequency? |
| A. | 0.0065 pF |
| B. | 0.0130 pF |
| C. | 0.0260 pF |
| D. | 0.520 pF |
| Answer» B. 0.0130 pF | |
| 2090. |
Equal amplitude ac signals are given as inputs to both inverting and given as inputs to both inverting and non-inverting terminals of an op-amp. The output will be zero when the phase difference between inputs is |
| A. | 0 |
| B. | 90 |
| C. | 180 |
| D. | 270 |
| Answer» B. 90 | |
| 2091. |
The oscillator shown in figure is a |
| A. | Clapp oscillator |
| B. | R-C Phase shift oscillator |
| C. | Hartley oscillator |
| D. | Colpitt's oscillator |
| Answer» B. R-C Phase shift oscillator | |
| 2092. |
In a combination limiter with sinusoidal input voltage the output wave can be nearly square. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 2093. |
A silicon PN junction diode under reverse bias has depletion region of width 10 m. The relative permittivity of silicon, r = 11.7 and the permittivity of free space 0 = 8.85 x 10-12 F/m. The depletion capacitance of the diode per square meter is |
| A. | 100 F |
| B. | 10 F |
| C. | 1 F |
| D. | 20 F |
| Answer» C. 1 F | |
| 2094. |
The input impedance of a non-inverting amplifier is very low. |
| A. | True |
| B. | False |
| Answer» C. | |
| 2095. |
Assertion (A): A Darlington amplifier has very low output impedanceReason (R): The circuit has a low resistance RE between emitter and ground |
| 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 | |
| 2096. |
RC oscillator can be used upto |
| A. | 1 kHz |
| B. | 10 kHz |
| C. | 50 kHz |
| D. | 100 kHz |
| Answer» C. 50 kHz | |
| 2097. |
In a N-P-N transistor of the emitter junction is reverse biased and collector junction is also reversed biased, the transistor will operate in |
| A. | active region |
| B. | saturation region |
| C. | cut-off region |
| D. | inverted region |
| Answer» D. inverted region | |
| 2098. |
Wide banding technique is employed in the |
| A. | video amplifier of a TV receiver |
| B. | IF amplifier of an FM receiver |
| C. | RF amplifier of an AM receiver |
| D. | input section of a communication receiver |
| Answer» B. IF amplifier of an FM receiver | |
| 2099. |
Assertion (A): The maximum efficiency of a class B push pull amplifier is 78.5%Reason (R): A current mirror uses a compensating diode in parallel with the emitter diode |
| 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 | |
| 2100. |
A two stage amplifier has an upper cutoff frequency of 2 MHz and a lower cutoff frequency of 2 MHz and a lower cut off frequency of 30 Hz. If both stages are similar, their individual upper and lower cut off frequencies respectively are |
| A. | 4 MHz and 60 MHz |
| B. | 3 MHz and 20 Hz |
| C. | 3 MHz and 60 Hz |
| D. | 4 MHz and 20 Hz |
| Answer» C. 3 MHz and 60 Hz | |