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.
| 2051. |
In figure the zener current |
| A. | is always 130 mA |
| B. | may vary between 10 mA and 130 mA |
| C. | may vary between 60 mA and 130 mA |
| D. | is always equal to 65 mA |
| Answer» C. may vary between 60 mA and 130 mA | |
| 2052. |
Two 3Ω speakers in series will have a total impedance of |
| A. | 1 Ω |
| B. | 3/2 Ω |
| C. | 3 Ω |
| D. | 6 Ω |
| Answer» C. 3 Ω | |
| 2053. |
In figure ID = 4 mA. Then VS = |
| A. | 20 V |
| B. | 4.4 V |
| C. | 0.4 V |
| D. | 0.44 V |
| Answer» C. 0.4 V | |
| 2054. |
A generator with an internal resistance of 600 Ω drives an amplifier whose input resistance is 400 Ω. The generator's open circuit voltages is 1 mV; the amplifier develops 100mV across an 8kΩ load. The voltage multiplication is |
| A. | 25 |
| B. | 50 |
| C. | 125 |
| D. | 250 |
| Answer» E. | |
| 2055. |
In a P-N-P transistor, with normal bias, the emitter junction |
| A. | is always reverse biased |
| B. | offers very high resistance |
| C. | offers a low resistance |
| D. | remains open |
| Answer» D. remains open | |
| 2056. |
The input gate current of a FET is |
| A. | a few amperes |
| B. | a few milli amperes |
| C. | a few micro amperes |
| D. | negligible |
| Answer» E. | |
| 2057. |
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 | |
| 2058. |
In figure, D2 turns on when |
| A. | vi is more positive than V1 |
| B. | vi is less positive than V1 |
| C. | vi is more negative than V2 |
| D. | vi is less negative than V2 |
| Answer» D. vi is less negative than V2 | |
| 2059. |
Figure represents |
| A. | Adder |
| B. | Multiplier |
| C. | Subtractor |
| D. | Log Amplifier |
| Answer» D. Log Amplifier | |
| 2060. |
The properties of FETs resemble closely to |
| A. | UJT |
| B. | current transformer |
| C. | thyristor |
| D. | thermionic valves |
| Answer» E. | |
| 2061. |
Which of the following is non-sinusoidal oscillator? |
| A. | Multivibrator |
| B. | Relaxation oscillator using UJT |
| C. | Relaxation oscillator using tunnel diode |
| D. | Any of the above |
| Answer» B. Relaxation oscillator using UJT | |
| 2062. |
For a BJT, β and a are related as |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» E. | |
| 2063. |
The IF amplifier in a superheterodyne receiver is |
| A. | single-stage single-timed amplifier |
| B. | two stage of single tuned amplifier |
| C. | double tuned amplifier |
| D. | class-C amplifier |
| Answer» C. double tuned amplifier | |
| 2064. |
A dc power supply has no load voltage of 30 V and full load voltage of 25 V at full load current of 1 A. The output resistance and voltage regulation respectively are |
| A. | 5 Ω and 25% |
| B. | 25 Ω and 20% |
| C. | 5 Ω and 16.7% |
| D. | 25 Ω and 16.7% |
| Answer» C. 5 Ω and 16.7% | |
| 2065. |
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 | |
| 2066. |
Assertion (A): In a circuit using FET, gate is approximately at dc groundReason (R): Self bias stabilizes the quiescent operating point against changes in JFET parameters |
| 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 | |
| 2067. |
To obtain very high I/P and O/P impedances in a feedback amplifier, the topology used is |
| A. | voltage series |
| B. | current series |
| C. | voltage shunt |
| D. | current shunt |
| Answer» D. current shunt | |
| 2068. |
Which of the following statement is false? |
| A. | The gate of DMOSFET may be biased positively, zero or negatively |
| B. | N-channel enhancement-only MOSFET conducts only when its gate is highly positive |
| C. | JFET has lower input impedance than MOSFET |
| D. | The bipolar base is forward biased, JFET gate must also be forward biased |
| Answer» E. | |
| 2069. |
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 | |
| 2070. |
When the ac input signal is very large the instantaneous operating point CE amplifier moves all the way between |
| A. | ac saturation and ac cut off points |
| B. | ac operating and ac cut off points |
| C. | ac saturation and ac operating points |
| D. | none of the above |
| Answer» B. ac operating and ac cut off points | |
| 2071. |
The input resistance Ri of the amplifier shown in the figure |
| A. | 30/40 kΩ |
| B. | 100 kΩ |
| C. | 40 kΩ |
| D. | ∞ |
| Answer» C. 40 kΩ | |
| 2072. |
Heat sink results in |
| A. | slower dissipation of heat to atmosphere |
| B. | faster dissipation of heat to atmosphere |
| C. | lower ambient temperature |
| D. | lower transistor power |
| Answer» C. lower ambient temperature | |
| 2073. |
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 | |
| 2074. |
In figure the trace on the CRO will be |
| A. | half rectifier wave |
| B. | clamped wave |
| C. | no trace at all |
| D. | either (a) or (b) |
| Answer» D. either (a) or (b) | |
| 2075. |
As compared to a bipolar transistor, a JFET is |
| A. | highly sensitive to changes in input voltage |
| B. | more sensitive to changes in input voltage |
| C. | less sensitive to changes in input voltage |
| D. | equally sensitive to changes in input voltage |
| Answer» D. equally sensitive to changes in input voltage | |
| 2076. |
In figure, VCC = + 30 V, R1 = 200 kΩ and R2 = 100 kΩ. If VBE = 0.7 V, the voltage a cross RE = |
| A. | +20 V |
| B. | +19.3 V |
| C. | +10 V |
| D. | +9.3 V |
| Answer» E. | |
| 2077. |
An engineer designs an amplifier to have a voltage gain of 60, but when constructed it only had a gain of 50. How much feedback should be used to provide the desired level? |
| A. | +0.03% |
| B. | +0.33% |
| C. | +1.30% |
| D. | +3.3% |
| Answer» C. +1.30% | |
| 2078. |
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 | |
| 2079. |
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 | |
| 2080. |
In a class C operation VCC = 40 V, RL = 50 Ω. The maximum load power can be |
| A. | 64 W |
| B. | 32 W |
| C. | 16 W |
| D. | 8 W |
| Answer» D. 8 W | |
| 2081. |
A semi-conductor device that behaves like two SCRs is |
| A. | UJT |
| B. | MOSFET |
| C. | JFET |
| D. | TRIAC |
| Answer» E. | |
| 2082. |
Turn off time of a transistor switch is equal to (where ts is storage time and tf is fall time.) |
| A. | ts + tf |
| B. | ts - tf |
| C. | 2ts |
| D. | 2tf |
| Answer» B. ts - tf | |
| 2083. |
Logarithmic amplifiers are used in |
| A. | adders |
| B. | dividers |
| C. | multipliers |
| D. | all of the above |
| Answer» C. multipliers | |
| 2084. |
Assertion (A): An op-amp has high voltage gain, high input impedance and low output impedanceReason (R): Negative feedback increases output impedance |
| 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 | |
| 2085. |
The gain of an FET amplifier can be changed by changing |
| A. | rm |
| B. | gm |
| C. | Rd |
| D. | none of the above |
| Answer» C. Rd | |
| 2086. |
If input frequency is 50 Hz, the frequency of output wave in a full wave diode rectifier circuit is |
| A. | 25 Hz |
| B. | 50 Hz |
| C. | 100 Hz |
| D. | 200 Hz |
| Answer» D. 200 Hz | |
| 2087. |
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. | |
| 2088. |
In a CE amplifier circuit the load resistance is open circuited. The output voltage will |
| A. | increase |
| B. | decrease |
| C. | become zero |
| D. | increase or decrease |
| Answer» B. decrease | |
| 2089. |
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 | |
| 2090. |
A transistor amplifier with 85% efficiency is expected to be |
| A. | class A |
| B. | class B |
| C. | class C |
| D. | class AB |
| Answer» D. class AB | |
| 2091. |
Which one of the following power amplifier has the maximum efficiency? |
| A. | Class A |
| B. | Class B |
| C. | Class AB |
| D. | Class C |
| Answer» E. | |
| 2092. |
CC circuit is suitable for impedance matching. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» B. False | |
| 2093. |
In a self bias circuit for CE amplifier, an increase in emitter resistance RE results in |
| A. | increase in emitter voltage |
| B. | decrease in emitter voltage |
| C. | increase in emitter current |
| D. | decrease in emitter current |
| Answer» E. | |
| 2094. |
A circuit using an op-amp is shown in the given figure. It has |
| A. | voltage series feedback |
| B. | voltage shunt feedback |
| C. | current shunt feedback |
| D. | current series feedback |
| Answer» C. current shunt feedback | |
| 2095. |
For the circuit of figure the critical frequency is |
| A. | 1/2πRC |
| B. | 1/πRC |
| C. | 2/πRC |
| D. | 4/πRC |
| Answer» C. 2/πRC | |
| 2096. |
The pinch-off voltage is the drain voltage on the shorted gate drain curve above which the drain current becomes |
| A. | almost negligible |
| B. | very high |
| C. | almost constant |
| D. | highly variable |
| Answer» D. highly variable | |
| 2097. |
For holding the drain current constant in spite of large changes in JFET parameters |
| A. | current source bias is used |
| B. | voltage divider bias is used |
| C. | reverse bias is used |
| D. | no bias is used |
| Answer» B. voltage divider bias is used | |
| 2098. |
A CE amplifier has a high input signal. In the wave shape of emitter current |
| A. | positive and negative half cycles will be symmetrical |
| B. | positive half cycle will be elongated and negative half cycle will be compressed |
| C. | positive half cycle will be compressed and negative half cycle will be elongated |
| D. | the half cycles may be either elongated or compressed |
| Answer» C. positive half cycle will be compressed and negative half cycle will be elongated | |
| 2099. |
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 | |
| 2100. |
In a class C power amplifier the input signal has a frequency of 250 kHz. If the collector current pulses are 0.1 μs wide, the duty cycle of current waveform is |
| A. | 50% |
| B. | 25% |
| C. | 2.5% |
| D. | 0.25% |
| Answer» D. 0.25% | |