MCQOPTIONS
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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.
| 1101. |
Low frequency response of amplifier is mainly limited by |
| A. | input capacitor |
| B. | bypass capacitor |
| C. | output capacitor |
| D. | biasing capacitor |
| Answer» C. output capacitor | |
| 1102. |
An inverting voltage feedback is a |
| A. | voltage amplifier |
| B. | current amplifier |
| C. | current to voltage converter |
| D. | voltage to current converter |
| Answer» D. voltage to current converter | |
| 1103. |
In the following figure C = 0.02 μF, and Vth is known to be of frequency ω = 10⁷ rad/sec and rd = 2.5 Ω and ZTh = RTh = 10 Ω Then phase angle between id and Vd |
| A. | 26.5° |
| B. | 25° |
| C. | 30° |
| D. | 0° |
| Answer» B. 25° | |
| 1104. |
A silicon PN junction diode under reverse bias has depletion region of width 10 μm. The relative permittivity of silicon, Ɛr = 11.7 and the permittivity of free space Ɛ₀ = 8.85 x 10¯¹² F/m. The depletion capacitance of the diode per square meter is |
| A. | 100 μF |
| B. | 10 μF |
| C. | 1 μF |
| D. | 20 μF |
| Answer» C. 1 μF | |
| 1105. |
A transistor in CE mode is in saturation region. Then the collector is almost at |
| A. | ground potential |
| B. | a potential equal to VCC |
| C. | a potential equal to 0.5 VCC |
| D. | a potential equal to 2 VCC |
| Answer» B. a potential equal to VCC | |
| 1106. |
Which of the following method cannot be used to increase the bandwidth for cascaded RF amplifier stages? |
| A. | Wave traps in each stage |
| B. | Stagger tuning |
| C. | A shunt damping resistor across each tuned circuit |
| D. | Doubled tuned transformers with tighter coupling |
| Answer» B. Stagger tuning | |
| 1107. |
For a transistor to have-a larger β it must have and a |
| A. | close to zero |
| B. | close to 0.5 |
| C. | close to unity |
| D. | nearly infinite |
| Answer» D. nearly infinite | |
| 1108. |
A three-section RC phase shift oscillator has R = 10K ohms and C = 0.001 μF. If the oscillator is to be made variable using the same value of R, what should be the value of capacitor to obtain a frequency if 1 kHz? |
| A. | 636 pF |
| B. | 180 pF |
| C. | 65 pF |
| D. | 30 pF |
| Answer» D. 30 pF | |
| 1109. |
The collector voltage VC of the circuit shown in the given figure aside is approximately |
| A. | 2 V |
| B. | 4.6 V |
| C. | 8 V |
| D. | 8.6 V |
| Answer» C. 8 V | |
| 1110. |
Which of the following best represents the bandwidth of an actual op-amp? |
| A. | 100 Hz to 1 MHz |
| B. | 0 Hz to 100 kHz |
| C. | 0 Hz to 10 MHz |
| D. | 0 Hz to infinity |
| Answer» C. 0 Hz to 10 MHz | |
| 1111. |
RC oscillator can be used upto |
| A. | 1 kHz |
| B. | 10 kHz |
| C. | 50 kHz |
| D. | 100 kHz |
| Answer» C. 50 kHz | |
| 1112. |
An amplifier has a large ac input signal. The clipping occurs on both the peaks. The output voltage will be nearly a |
| A. | sine wave |
| B. | square wave |
| C. | triangular wave |
| D. | (a) or (c) |
| Answer» C. triangular wave | |
| 1113. |
It is desired to reduce distortion in an amplifier from 8% to 2% by using 5% negative feedback. The open and closed loop gains respectively are |
| A. | 60 and 15 |
| B. | 15 and 60 |
| C. | 6 and 1.5 |
| D. | 1.5 and 6 |
| Answer» B. 15 and 60 | |
| 1114. |
The changes in ambient temperature affect the open loop gain of amplifier. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» B. False | |
| 1115. |
For a transistor the normal collector voltage is 12 V. If actually it is found to be + 28 V, the trouble could be |
| A. | RL is open |
| B. | RE is open |
| C. | CE is shorted |
| D. | CE is open |
| Answer» C. CE is shorted | |
| 1116. |
At midband frequencies the coupling capacitor in RC coupled CE amplifier may be considered as |
| A. | open circuit |
| B. | short circuit |
| C. | a reactance equal to load resistance |
| D. | none of the above |
| Answer» C. a reactance equal to load resistance | |
| 1117. |
For the amplifier in figure, β = 800. The mid-band voltage gain V0/Vi is |
| A. | 0 |
| B. | < 1 |
| C. | ≈ 1 |
| D. | 800 |
| Answer» D. 800 | |
| 1118. |
The theoretical maximum efficiency of a half wave diode rectifier is |
| A. | 40.6% |
| B. | 50% |
| C. | 81.2% |
| D. | slightly less than 100% |
| Answer» B. 50% | |
| 1119. |
Assertion (A): In class A amplifier the distortion is minimumReason (R): In class A amplifier collector current exists for 360° of input cycle |
| 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 | |
| 1120. |
The voltage gains of an amplifier without feedback and with negative feedback respectively are 100 and 20. The percentage of negative feedback (β) would be |
| A. | 40% |
| B. | 5% |
| C. | 20% |
| D. | 80% |
| Answer» B. 5% | |
| 1121. |
In CC configuration, the output signals has approximately |
| A. | the same amplitude and phase |
| B. | opposite amplitude and phase |
| C. | same amplitude but opposite phase |
| D. | none of the above |
| Answer» B. opposite amplitude and phase | |
| 1122. |
Which of the following h parameters is an admittance? |
| A. | hie |
| B. | hre |
| C. | hfe |
| D. | hoe |
| Answer» E. | |
| 1123. |
The symbol shown in figure represents a |
| A. | P-channel MOSFET |
| B. | UJT with N-type base |
| C. | N-channel DEMOSFET with internal zener protection |
| D. | P-channel DEMOSFET with internal zener protection |
| Answer» D. P-channel DEMOSFET with internal zener protection | |
| 1124. |
A low noise device is most important |
| A. | at front end of equipment |
| B. | in the last stage of equipment |
| C. | in the middle stages of equipment |
| D. | both (b) and (c) |
| Answer» B. in the last stage of equipment | |
| 1125. |
Which of the following power amplifiers has highest efficiency? |
| A. | Class A |
| B. | Class AB |
| C. | Class B |
| D. | Class C |
| Answer» E. | |
| 1126. |
When Z1 |
| A. | inverting amplifier |
| B. | Schmitt trigger |
| C. | non-inverting amplifier |
| D. | source follower |
| Answer» E. | |
| 1127. |
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 | |
| 1128. |
If the output current wave shape of class C circuit has a period of 1 μs and a pulse width of 0.006 μs, the duty cycle is |
| A. | 6% |
| B. | 0.6% |
| C. | 0.006% |
| D. | 0.06% |
| Answer» C. 0.006% | |
| 1129. |
To have a centred Q point in CE amplifier |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 1130. |
funity of an op-amp is about 1 kHz. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» C. May be True or False | |
| 1131. |
The circuit shown I/P in the figure represents |
| A. | Low pass filter |
| B. | High pass filter |
| C. | Band Pass filter |
| D. | Band stop filter |
| Answer» D. Band stop filter | |
| 1132. |
Which of the following uses a capacitor in the feedback path? |
| A. | Active low pass filter |
| B. | Active high pass filter |
| C. | Both (a) or (b) |
| D. | Neither (a) nor (b) |
| Answer» B. Active high pass filter | |
| 1133. |
Consider the following statements : A clamper circuit 1. adds or subtracts a dc voltage to a waveform2. does not change the waveform3. amplifiers the waveform Which are correct? |
| A. | 1, 2 |
| B. | 1, 3 |
| C. | 1, 2, 3 |
| D. | 2, 3 |
| Answer» B. 1, 3 | |
| 1134. |
In the equivalent circuit of figure voltage gain is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 1135. |
Which of the following is the fastest switching device? |
| A. | JFET |
| B. | BJT |
| C. | MOSFET |
| D. | Triode |
| Answer» D. Triode | |
| 1136. |
The minimum gate source voltage that creates the n-type inversion layer is called |
| A. | cut off voltage |
| B. | on voltage |
| C. | threshold voltage |
| D. | zener voltage |
| Answer» D. zener voltage | |
| 1137. |
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. | 20% |
| B. | 2% |
| C. | 0.5% |
| D. | 0.05% |
| Answer» D. 0.05% | |
| 1138. |
When a transistor is to be at a temperature above 25°C |
| A. | smaller heat sink be provided |
| B. | maximum power rating be derated |
| C. | biasing circuit must be strengthened |
| D. | earth connections must be connected through a resistor |
| Answer» C. biasing circuit must be strengthened | |
| 1139. |
In a CE amplifier drives a low load resistance directly the result will be |
| A. | overloading of amplifier |
| B. | underloading of amplifier |
| C. | overloading or underloading of amplifier depending on circuit |
| D. | none of the above |
| Answer» B. underloading of amplifier | |
| 1140. |
The efficiency of a full wave rectifier using centre tapped transformer is twice that in full wave bridge rectifier. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» C. May be True or False | |
| 1141. |
Which of the following circuit would be preferred for a 355 KHz IF amplifier? |
| A. | Resistance loaded |
| B. | Double tuned transformer |
| C. | Video amplifier |
| D. | Class C |
| Answer» C. Video amplifier | |
| 1142. |
A potential of 7 V is applied to a silicon diode. A resistance of 1 kΩ is also connected in series. If the diode is forward biased, the current in the circuit is |
| A. | 7 mA |
| B. | 6.3 mA |
| C. | 0.7 mA |
| D. | 0 |
| Answer» C. 0.7 mA | |
| 1143. |
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 | |
| 1144. |
Assertion (A): In CC amplifier the collector is at ac ground Reason (R): CC amplifier is also called emitter follower |
| 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 | |
| 1145. |
The use of a capacitor filter in a rectifier circuit gives satisfactory performance only when the load |
| A. | current is high |
| B. | current is low |
| C. | voltage is high |
| D. | voltage is low |
| Answer» C. voltage is high | |
| 1146. |
Efficiency of a half wave diode rectifier is less than 40%. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» B. False | |
| 1147. |
The main use of JFET with a |
| A. | frequency mixer |
| B. | source follower |
| C. | voltage doubler |
| D. | trigger |
| Answer» C. voltage doubler | |
| 1148. |
As the ratio Rf/RL increases the efficiency of a rectifier increases. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» C. May be True or False | |
| 1149. |
In the figure, assume the op-amp is to be ideal. The output Vo if the circuit is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 1150. |
A second-order band-pass active filter can be obtained by cascading a low pass second order section having cut off frequency fOH with a high pass second order section having cut-off frequency fOL provided |
| A. | fOH > fOL |
| B. | fOH < fOL |
| C. | fOH = fOL |
| D. | fOH ≤ 1/2fOL |
| Answer» B. fOH < fOL | |