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.
| 1501. |
The emitter coupled pair of BJT's gives a linear transfer relation between the differential output voltage and the differential input voltage Vid only when the magnitude of Vid is less a times the thermal voltage, where α is |
| A. | 4 |
| B. | 3 |
| C. | 2 |
| D. | 1 |
| Answer» E. | |
| 1502. |
In a CE amplifier the Q point is very close to saturation point on the dc load line. This results in |
| A. | positive clipping of collector current |
| B. | negative clipping of collector current |
| C. | both positive and negative clipping of collector current |
| D. | either positive or negative clipping of collector current |
| Answer» B. negative clipping of collector current | |
| 1503. |
In most transistor the collector region is made physically larger than the emitter region |
| A. | for dissipating heat |
| B. | to distinguish it from other regions |
| C. | as it is sensitive to ultraviolet rays |
| D. | to reduce resistance in the path of flow of electrons |
| Answer» B. to distinguish it from other regions | |
| 1504. |
The slope of the transfer characteristics of an N-channel JFET is |
| A. | positive |
| B. | negative |
| C. | constantly varying |
| D. | zero |
| Answer» C. constantly varying | |
| 1505. |
In a rectifier only a portion of input power is converted into DC power. The rest is AC power. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» B. False | |
| 1506. |
In a current mirror |
| A. | the i - v curve of compensating diode is similar to collector curve of transistor |
| B. | the i - v curve of compensating diode is similar to transconductance curve of transistor |
| C. | either (a) or (b) |
| D. | neither (a) nor (b) |
| Answer» C. either (a) or (b) | |
| 1507. |
The common gate amplifier has a characteristically __________ input resistance and a __________ output resistance. |
| A. | low, low |
| B. | high, high |
| C. | low, high |
| D. | high, low |
| Answer» D. high, low | |
| 1508. |
In the case of an amplifier, the normalised voltage gain is given by.where f0 is zero frequency, fP is pole frequency. For a standard frequency response of the amplifier, |
| A. | fP >> f0 |
| B. | fP = f0 |
| C. | fP << f0 |
| D. | f0 = 2 fP |
| Answer» B. fP = f0 | |
| 1509. |
CMRR is the ratio of differential voltage gain to common mode gain. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» B. False | |
| 1510. |
The purpose of impedance matching in an amplifier circuit is to achieve |
| A. | high efficiency |
| B. | reduce distortion |
| C. | maximum power transfer |
| D. | none of the above |
| Answer» D. none of the above | |
| 1511. |
Which mode is usually preferred for cascading? |
| A. | CE |
| B. | CB |
| C. | CC |
| D. | Any of the above |
| Answer» B. CB | |
| 1512. |
In a diode rectifier with a capacitance input filter, a surge current is likely to flow when the circuit is switched on. The cause of this surge current is |
| A. | the non linear behaviour of diodes |
| B. | the capacitor acts as a short circuit at the instant of switching, |
| C. | the inductance of leads |
| D. | both (a) and (b) |
| Answer» C. the inductance of leads | |
| 1513. |
In switching devices, gold doping is used to |
| A. | improve bonding |
| B. | reduce storage time |
| C. | increase the mobility of the carrier |
| D. | protect the terminals against cooperation |
| Answer» C. increase the mobility of the carrier | |
| 1514. |
Which of the following amplifier circuit using junction transistor has the best gain? |
| A. | Common base |
| B. | Common emitter |
| C. | Common collector |
| D. | All have the same gain |
| Answer» C. Common collector | |
| 1515. |
In an op-amp differentiator |
| A. | the amplitude of output is proportional to rate of change of input |
| B. | the amplitude of output is proportional to input |
| C. | output occurs when input is finite and constant |
| D. | polarity of input and output is the same |
| Answer» B. the amplitude of output is proportional to input | |
| 1516. |
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 | |
| 1517. |
In a CB amplifier the maximum efficiency could be |
| A. | 99% |
| B. | 85% |
| C. | 50% |
| D. | 25% |
| Answer» E. | |
| 1518. |
In a transistor leakage current mainly depends on |
| A. | doping of base |
| B. | size of emitter |
| C. | rating of transistor |
| D. | temperature |
| Answer» E. | |
| 1519. |
Assertion (A): A good op-amp should have very large band widthReason (R): An ideal op-amp should have infinite input resistance and zero output resistance |
| 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 | |
| 1520. |
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 input signal-to noise ratio is |
| A. | 2 |
| B. | 10 |
| C. | 20 |
| D. | 100 |
| Answer» E. | |
| 1521. |
In CE approximately, the active region is where the collector curves are |
| A. | almost horizontal |
| B. | almost vertical |
| C. | inclined at 45° |
| D. | inclined at 60° |
| Answer» B. almost vertical | |
| 1522. |
A certain transistor has αdc of 0.98 and a collectors leakage current of 5 μA. If IE = 1 mA, the base current will be |
| A. | 35 μA |
| B. | 25 μA |
| C. | 15 μA |
| D. | 5 μA |
| Answer» D. 5 μA | |
| 1523. |
For a BJT if β = 50, ICEO = 3 μA and IC = 1.2 mA then IE |
| A. | 1 mA |
| B. | 1.2 mA |
| C. | 1.3 mA |
| D. | 1.4 mA |
| Answer» C. 1.3 mA | |
| 1524. |
Which of the following amplifier circuits has highest input impedance? |
| A. | Circuit using BJT |
| B. | Circuit using JFET |
| C. | Circuit using MOSFET |
| D. | Either (a) or (b) |
| Answer» D. Either (a) or (b) | |
| 1525. |
CMRR of an op-amp is about 0.1. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» C. May be True or False | |
| 1526. |
If the Q of a single-stage single-tuned amplifier is doubled, then its bandwidth will |
| A. | remain same |
| B. | become half |
| C. | become doubled |
| D. | become four times |
| Answer» C. become doubled | |
| 1527. |
The noise figure of FET circuit is |
| A. | independent of the quiescent point |
| B. | dependent on the quiescent point only |
| C. | dependent on the triggering mechanism |
| D. | independent of all above |
| Answer» B. dependent on the quiescent point only | |
| 1528. |
In a power amplifier the collector current flows for 270° of the input cycle. The operations is |
| A. | class A |
| B. | class B |
| C. | class AB |
| D. | class C |
| Answer» D. class C | |
| 1529. |
For a transistor if αdc = 0.98 and emitter current IE is 2 mA, then base current will be |
| A. | 10 μA |
| B. | 40 μA |
| C. | 80 μA |
| D. | 200 μA |
| Answer» B. 40 μA | |
| 1530. |
An ideal voltage amplifier should have |
| A. | low input impedance and high output impedance |
| B. | high input impedance and low output impedance |
| C. | high input impedance and high output impedance |
| D. | low input impedance and low output impedance |
| Answer» C. high input impedance and high output impedance | |
| 1531. |
The self bias provides |
| A. | stable Q point |
| B. | large voltage gain |
| C. | high input impedance |
| D. | high base current |
| Answer» B. large voltage gain | |
| 1532. |
A class A transformer coupled power amplifier is to deliver 10 W output. The power rating of transistor should not be less than |
| A. | 5 W |
| B. | 10 W |
| C. | 20 W |
| D. | 40 W |
| Answer» D. 40 W | |
| 1533. |
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 | |
| 1534. |
When the emitter current of a transistor is changed by 1 mA, its collector current changes by 0.990 mA. The common base short circuit current gain a for the transistor is |
| A. | 0.99 |
| B. | 1.01 |
| C. | 1.001 |
| D. | 0.990 |
| Answer» B. 1.01 | |
| 1535. |
Assertion (A): A resistor is a passive load and a transistor is an active loadReason (R): Op-amp is mostly used in feedback mode |
| 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 | |
| 1536. |
High frequency oscillations can be caused by |
| A. | electric coupling |
| B. | magnetic coupling |
| C. | ground loop |
| D. | all of the above |
| Answer» E. | |
| 1537. |
The feedback technique employed in the following circuit is |
| A. | voltage series feedback |
| B. | current series feedback |
| C. | voltage shunt feedback |
| D. | current shunt feedback |
| Answer» D. current shunt feedback | |
| 1538. |
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 noise factor is |
| A. | 1 |
| B. | 1.5 |
| C. | 2.0 |
| D. | 15 |
| Answer» D. 15 | |
| 1539. |
Class C operation finds application in |
| A. | RF power amplifiers |
| B. | frequency multipliers |
| C. | both (a) and (b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 1540. |
Assertion (A): The main use of Miller integrator is to generate rampReason (R): An inverting amplifier can handle more than one input at the same time. |
| 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 | |
| 1541. |
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 | |
| 1542. |
In a JFET, the lower end is called the __________ and the upper end is called the __________ . |
| A. | source, channel |
| B. | channel, drain |
| C. | source, drain |
| D. | drain source |
| Answer» D. drain source | |
| 1543. |
n-channel MOS is |
| A. | slower than p-channel MOS |
| B. | faster than p-channel MOS |
| C. | same as p-channel MOS |
| D. | none of these |
| Answer» C. same as p-channel MOS | |
| 1544. |
Tuned amplifiers are used at radio frequencies. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» B. False | |
| 1545. |
Most small signal transistors are |
| A. | N-P-N, silicon, in a plastic package |
| B. | P-N-P, silicon, in a plastic package |
| C. | N-P-N, germanium in a metallic case |
| D. | P-N-P, germanium in a metallic case |
| Answer» B. P-N-P, silicon, in a plastic package | |
| 1546. |
In a transistor E mode the collector current with the transistor in cut off region is |
| A. | zero |
| B. | high |
| C. | equal to saturated value |
| D. | none of the above |
| Answer» B. high | |
| 1547. |
In a class C operation VCC = 40 V and VCE(sat) = 0.4 V. The efficiency is |
| A. | 90% |
| B. | 49.5% |
| C. | 1% |
| D. | 0.5% |
| Answer» B. 49.5% | |
| 1548. |
In figure, VC is approximately equal to |
| A. | 2 V |
| B. | 4.6 V |
| C. | 8 V |
| D. | 7.6 V |
| Answer» D. 7.6 V | |
| 1549. |
In a good voltage amplifier, its input impedance |
| A. | must be high compared to the resistance of the source |
| B. | must be low compared to the resistance of the source |
| C. | must be equal to the resistance of the source |
| D. | must be half the resistance of the source |
| Answer» B. must be low compared to the resistance of the source | |
| 1550. |
In CE amplifier circuit, voltage gain is directly proportional to |
| A. | β |
| B. | collector supply voltage |
| C. | base resistance |
| D. | none of the above |
| Answer» B. collector supply voltage | |