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.
| 1901. |
The JFET in the circuit shown in figure has an IDSS = 10 mA and Vp = -5V. The value of the resistance Rs for a drain current IDS = 6.4 mA is |
| A. | 156 Ω |
| B. | 470 Ω |
| C. | 560 Ω |
| D. | 1 kΩ |
| Answer» B. 470 Ω | |
| 1902. |
The enhancement type MOSFET is called a |
| A. | normally on MOSFET |
| B. | normally off MOSFET |
| C. | P-type MOSFET |
| D. | N-type MOSFET |
| Answer» C. P-type MOSFET | |
| 1903. |
In figure the potential of gate terminal is |
| A. | 4 V |
| B. | -4 V |
| C. | 0 |
| D. | 20 V |
| Answer» D. 20 V | |
| 1904. |
In the circuit shown in the figure, the approximate voltage at the transistor, |
| A. | base and emitter respectively are -8 V and -7.3 V |
| B. | base and collector respectively are -8 V and -5 V |
| C. | Collector and emitter respectively are -5 V and -7.3 |
| D. | base, emitter and collector respectively are -8 V, 7.3 V and -5 V |
| Answer» E. | |
| 1905. |
Oscillation of frequency in Hartley oscillator is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 1906. |
A differential amplifier consists of two CB amplifiers. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» C. May be True or False | |
| 1907. |
For a good voltage amplifier, its input impedance should be |
| A. | low as compared to the resistance of the source |
| B. | high as compared to the resistance of the source |
| C. | always inductive |
| D. | always capacitive |
| Answer» C. always inductive | |
| 1908. |
A CE amplifier has re = 6 Ω, β = 100 and a = 0.98. The input impedance is |
| A. | 6 Ω |
| B. | 100 Ω |
| C. | 600 Ω |
| D. | 98 Ω |
| Answer» D. 98 Ω | |
| 1909. |
The transistor specification number 2N refers to |
| A. | triac |
| B. | diac |
| C. | junction transistor |
| D. | FET with one gate |
| Answer» D. FET with one gate | |
| 1910. |
The P-type substrate in a conventional pn Junction isolated integrated circuits should be connected to |
| A. | any where |
| B. | a dc ground potential |
| C. | the most positive potential available in the circuit |
| D. | the most negative potential available in the circuit |
| Answer» D. the most negative potential available in the circuit | |
| 1911. |
For the circuit shown in the figure, the capacitor C is initially uncharged. At t = 0, the switch S is closed. The voltage Vc across the capacitor at t = 1 millisecond is (In the figure shown above, the op-amp is supplied with ± 15 V and the ground has been shown by the symbol) |
| A. | 0 V |
| B. | 6.3 V |
| C. | 9.45 volts |
| D. | 10 volts |
| Answer» E. | |
| 1912. |
The current flowing in a certain P-N junction at room temperature is 2 x 10¯⁷ Amp. When a large reverse biased voltage is applied. Calculate the current flowing when 0.1 volts is applied. |
| A. | 9 μA |
| B. | 10 μA |
| C. | 2 μA |
| D. | 4 μA |
| Answer» B. 10 μA | |
| 1913. |
A three-section RC phase shift oscillator has R = 10K ohms and C = 0.001 μF. The frequency of oscillations is |
| A. | 1.1 kHz |
| B. | 2.5 kHz |
| C. | 3.3 kHz |
| D. | 6.5 kHz |
| Answer» E. | |
| 1914. |
In calculating output impedance of an amplifier the source is replaced by an open circuit. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» C. May be True or False | |
| 1915. |
The slew rate of an ideal op-amp is |
| A. | very slow |
| B. | slow |
| C. | fast |
| D. | infinitely fast |
| Answer» E. | |
| 1916. |
Assertion (A): An op-amp amplifier can amplify dc signalReason (R): An op-amp amplifier is a direct coupled amplifier |
| 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 | |
| 1917. |
A boot strap generally incorporates |
| A. | CB configuration |
| B. | CE configuration |
| C. | emitter follower |
| D. | none of the above |
| Answer» B. CE configuration | |
| 1918. |
The heat sink disposes off heat mainly by |
| A. | radiation |
| B. | natural convection |
| C. | forced convection |
| D. | conduction |
| Answer» C. forced convection | |
| 1919. |
A Wien bridge oscillator uses Wien bridge for |
| A. | tuning and phase shift |
| B. | tuning |
| C. | phase shift |
| D. | either tuning or phase shift |
| Answer» B. tuning | |
| 1920. |
The advantage of Weinbridge oscillator over the phase shift oscillator is that oscillator the frequency may be varied over a range of |
| A. | 1 : 2 |
| B. | 1 : 3 |
| C. | 1 : 5 |
| D. | 1 : 10 |
| Answer» E. | |
| 1921. |
A transconductance amplifier has |
| A. | high input impedance and low output impedance |
| B. | low input impedance and high output impedance |
| C. | high input and output impedance |
| D. | low input and output impedance |
| Answer» D. low input and output impedance | |
| 1922. |
As a compared to a CB amplifier, a CE amplifier has |
| A. | lower current amplification |
| B. | higher current amplification |
| C. | lower input resistance |
| D. | higher input resistance |
| Answer» C. lower input resistance | |
| 1923. |
Ultra high frequency oscillators work in the range |
| A. | 20 Hz to 20 kHz |
| B. | 1 kHz to 30 kHz |
| C. | 30 kHz to 30 MHz |
| D. | above 30 MHz |
| Answer» E. | |
| 1924. |
A full wave diode rectifier using centre tapped transformer has diodes with forward resistance of 50 ohms each. The load resistance of 50 ohms each. The load resistance is also 50 ohms. The voltage regulation is |
| A. | 20% |
| B. | 50% |
| C. | 100% |
| D. | 200% |
| Answer» D. 200% | |
| 1925. |
In figure VBE = 0.7 V. If base current required to saturate the transistor is 0.1 mA, Vi = |
| A. | 5 V |
| B. | 5.7 V |
| C. | 10 V |
| D. | 10.7 V |
| Answer» C. 10 V | |
| 1926. |
In figure, V0 = |
| A. | -1 V |
| B. | 2 V |
| C. | +1 V |
| D. | +15 V |
| Answer» C. +1 V | |
| 1927. |
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. | |
| 1928. |
IN 3242 is a |
| A. | P-N-P transistor |
| B. | N-P-N transistor |
| C. | UJT |
| D. | semi-conductor diode |
| Answer» E. | |
| 1929. |
The gate-source voltage that reduces the drain current to approximately zero is called |
| A. | gate-source on voltage |
| B. | gate-source voltage |
| C. | pinch-off voltage |
| D. | gate-source cut-off voltage |
| Answer» D. gate-source cut-off voltage | |
| 1930. |
For class B operation the theoretical maximum efficiency is |
| A. | 100% |
| B. | 78.5% |
| C. | 50% |
| D. | 27.5% |
| Answer» C. 50% | |
| 1931. |
An exponential amplifier has diode in feedback path. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» C. May be True or False | |
| 1932. |
Feedback factor may be less or more than 1. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» C. May be True or False | |
| 1933. |
If three cascaded stages of amplifier have gains 10, 20 and 30 the overall voltage will be |
| A. | 30 |
| B. | 60 |
| C. | 600 |
| D. | 6000 |
| Answer» E. | |
| 1934. |
In a tuned class C power amplifier the quiescent value of collector to emitter voltage is equal to (VCC denotes collector battery voltage) |
| A. | VCC |
| B. | 0.5 VCC |
| C. | 0.25 VCC |
| D. | either (b) or (c) |
| Answer» B. 0.5 VCC | |
| 1935. |
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 | |
| 1936. |
When a 1 V increase in gate voltage changes the drain current 10 mA in an FET, its gm equals |
| A. | 10 μμ |
| B. | 100 μμ |
| C. | 1000 μμ |
| D. | 10000 μμ |
| Answer» E. | |
| 1937. |
A distorted sinusoidal has the amplitudes A1, A2, A3 ... of the fundamental, second, harmonic third harmonic, ... respectively. The total harmonic distortion is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 1938. |
The ac input voltage of an amplifier |
| A. | is always equal to ac signal voltage |
| B. | may be equal to or more than ac signal voltage |
| C. | is always less than ac signal voltage |
| D. | may be equal or more or less than ac signal voltage |
| Answer» E. | |
| 1939. |
For operation of enhancement only N-channel MOSFET, value of gate voltage has to be |
| A. | zero |
| B. | low positive |
| C. | high negative |
| D. | high positive |
| Answer» E. | |
| 1940. |
A FET |
| A. | has two P-N junctions |
| B. | has three P-N junctions |
| C. | depends on the variation of the depletion layer width with reverse voltage, for its operation |
| D. | depends on the variation of a magnetic field for its operation |
| Answer» C. depends on the variation of the depletion layer width with reverse voltage, for its operation | |
| 1941. |
In figure, VG = |
| A. | 2.22 V |
| B. | 22.2 V |
| C. | 0.22 V |
| D. | 0.022 V |
| Answer» B. 22.2 V | |
| 1942. |
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 | |
| 1943. |
A transistor with a = 0.9 and ICBO = 10 μA is biased so that IBQ = 90 μA. Then IEQ will be |
| A. | 5.15 mA |
| B. | 5.2 mA |
| C. | 5 mA |
| D. | 990 mA |
| Answer» E. | |
| 1944. |
The parameter h11 for CB circuit is higher than that for CE circuit. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» C. May be True or False | |
| 1945. |
In the case of the circuit shown in the figure, the collector current IC will be, if β = 100, VBE = 0.7 V, ICO = 0.1 βA at 20°C |
| A. | 2.26 mA |
| B. | 1.85 mA |
| C. | 0.357 mA |
| D. | 0.185 mA |
| Answer» B. 1.85 mA | |
| 1946. |
The ripple factor of a full wave rectifier is about 0.5. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» B. False | |
| 1947. |
Two identical FETs each having parameters gm and rd are connected is parallel. The composite FET has parameters |
| A. | 0.5 gm and 2 rd |
| B. | 0.5 gm and 0.5 rd |
| C. | 2 gm and 2 rd |
| D. | 2 gm and 0.5 rd |
| Answer» E. | |
| 1948. |
If the thermal resistance of a transistor is lower it means |
| A. | higher junction temperature |
| B. | lower junction temperature |
| C. | higher or lower junction temperature depending on circuit conditions |
| D. | higher or lower junction temperature depending on transistor |
| Answer» C. higher or lower junction temperature depending on circuit conditions | |
| 1949. |
Regulation of the DC power supply of 12 V, 100 mA is the effective resistance of power supply is 20 Ω |
| A. | 22% |
| B. | 131% |
| C. | 30% |
| D. | 20% |
| Answer» E. | |
| 1950. |
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 | |