MCQOPTIONS
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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.
| 1601. |
D-layer extends approximately from |
| A. | 50 to 90 km |
| B. | 20 to 50 km |
| C. | 90 to 110 km |
| D. | up to 50 km |
| Answer» B. 20 to 50 km | |
| 1602. |
For a hollow waveguide, the axial current must necessarily be |
| A. | combination of conduction and displacement current |
| B. | conduction current only |
| C. | time varying conduction current and displacement current |
| D. | displacement current only |
| Answer» E. | |
| 1603. |
Antenna beamwidth is |
| A. | measure of directivity |
| B. | measure of angle |
| C. | measure of radiation pattern |
| D. | measure of power pattern |
| Answer» B. measure of angle | |
| 1604. |
What is the characteristic impedance Z0 of a line having R, inductance L, capacitance C and conductance G? |
| A. | <img src="/_files/images/electronics-and-communication-engineering/electromagnetic-field-theory/200-309-1.png"> |
| B. | <img src="/_files/images/electronics-and-communication-engineering/electromagnetic-field-theory/200-309-2.png"> |
| C. | <img src="/_files/images/electronics-and-communication-engineering/electromagnetic-field-theory/200-309-3.png"> |
| D. | <img src="/_files/images/electronics-and-communication-engineering/electromagnetic-field-theory/200-309-4.png"> |
| Answer» B. <img src="/_files/images/electronics-and-communication-engineering/electromagnetic-field-theory/200-309-2.png"> | |
| 1605. |
Which of the following is high frequency transmission line? |
| A. | An impedance transformer |
| B. | Frequency compensator |
| C. | Flying resistor |
| D. | None of the above |
| Answer» B. Frequency compensator | |
| 1606. |
Frequencies in the UHF range propagate by means of |
| A. | space wave |
| B. | surface waves |
| C. | sky waves |
| D. | ground waves |
| Answer» B. surface waves | |
| 1607. |
Microwave signals follow the curvature of the earth and the phenomenon |
| A. | tropospheric scatter |
| B. | faraday effect |
| C. | duct propagation |
| D. | none |
| Answer» D. none | |
| 1608. |
T.V. broadcasting based on |
| A. | line of sight communication |
| B. | ionospheric propagation |
| C. | ground wave |
| D. | medium wave |
| Answer» C. ground wave | |
| 1609. |
An antenna is considered to be in free space where its height above the ground is |
| A. | |
| B. | 2 |
| C. | less than 3 |
| D. | more than 5 |
| Answer» E. | |
| 1610. |
Poynting vector signifies which of the following? |
| A. | Power density vector producing electrostatic field |
| B. | Power density vector producing electromagnetic field |
| C. | Current density vector producing electrostatic field |
| D. | Current density vector producing electromagnetic field |
| Answer» C. Current density vector producing electrostatic field | |
| 1611. |
At room temperature kT = 0.03 eV. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 1612. |
An extrinsic semiconductor sample has 6 billion silicon atoms and 3 million pentavalent impurity atoms. The number of electrons and holes is |
| A. | 3 million each |
| B. | 6 billion each |
| C. | 3 million free electrons and very small number of holes |
| D. | 3 million holes and very small number of free electrons |
| Answer» D. 3 million holes and very small number of free electrons | |
| 1613. |
Consider the following statement: At finite temperature, magnetic dipoles in a material are randomly oriented giving low magnetization. When magnetic field H is applied, the magnetization? Increases with HDecreases with HDecreases with temp for constant H Which of the statement given above is/are correct? |
| A. | 1 |
| B. | 2 |
| C. | 2, 3 |
| D. | 1 and 3 |
| Answer» E. | |
| 1614. |
The amount of time between the creation and disappearance of a hole in an intrinsic semiconductor material is called |
| A. | life cycle |
| B. | recombination time |
| C. | life time |
| D. | half life |
| Answer» D. half life | |
| 1615. |
Lowest noise can be expected in case of |
| A. | carbon composition resistors |
| B. | carbon film resistors |
| C. | tin oxide resistors |
| D. | metal film resistors |
| Answer» E. | |
| 1616. |
EG for silicon is 1.12 eV and that for germanium is 0.72 eV. Therefore it can be concluded that |
| A. | more number of electron-hole pairs will be generated in silicon than in germanium at room temperature |
| B. | less number of electron hole pairs will be generated in silicon than in germanium at room temperature |
| C. | equal number of electron-hole pairs will be generated in both at lower temperatures |
| D. | equal number of electron-hole pairs will be generated in both at higher temperatures |
| Answer» C. equal number of electron-hole pairs will be generated in both at lower temperatures | |
| 1617. |
Fill in the suitable word in the blanks is the following questions. The electron in the outermost orbit is called __________ electron. |
| A. | valence |
| B. | covalent |
| C. | acceptor |
| D. | donor |
| Answer» B. covalent | |
| 1618. |
DeMorgan's first theorem shows the equivalence of |
| A. | OR gate and Exclusive OR gate |
| B. | NOR gate and Bubbled AND gate |
| C. | NOR gate and NAND gate |
| D. | NAND gate and NOT gate |
| Answer» C. NOR gate and NAND gate | |
| 1619. |
In the given figure, the flip flop is |
| A. | negative edge triggered |
| B. | positive edge triggered |
| C. | level triggered |
| D. | either (a) or (c) |
| Answer» B. positive edge triggered | |
| 1620. |
A decade counter skips |
| A. | binary states 1000 to 1111 |
| B. | binary states 0000 to 0011 |
| C. | binary states 1010 to 1111 |
| D. | binary states 1111 to higher |
| Answer» D. binary states 1111 to higher | |
| 1621. |
A ring counter with 5 flip flops will have |
| A. | 5 states |
| B. | 10 states |
| C. | 32 states |
| D. | infinite states |
| Answer» B. 10 states | |
| 1622. |
The minimum number of NAND gates required to implement the Boolean function A +AB + ABC is equal to |
| A. | 0 |
| B. | 1 |
| C. | 4 |
| D. | 7 |
| Answer» B. 1 | |
| 1623. |
The quiescent collector current IC, and collector to emitter voltage VCE in a CE connection are the values when |
| A. | ac signal is zero |
| B. | ac signal is low |
| C. | ac signal is negative |
| D. | either (a) or (b) |
| Answer» B. ac signal is low | |
| 1624. |
A transistor has two p-n junctions. The batteries should be connected such that |
| A. | both junctions are forward biased |
| B. | both junctions are reverse biased |
| C. | one junction is forward biased and the other is reverse biased |
| D. | either (a) or (b) |
| Answer» D. either (a) or (b) | |
| 1625. |
Assertion (A): In an op-amp the voltage gain and band width can be adjusted as per requirementReason (R): Large value capacitor can also be fabricated on a chip |
| 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 | |
| 1626. |
In a BJT amplifier the power gain from base to collector is 4000. The power gain in dB is |
| A. | 3.6 |
| B. | 36 |
| C. | 7.2 |
| D. | 72 |
| Answer» C. 7.2 | |
| 1627. |
Typical values of current gains for CE, CB and CC amplifiers are |
| A. | 120, 120 and 1 respectively |
| B. | 120, 1 and 120 respectively |
| C. | 1, 120 and 120 respectively |
| D. | 1, 1 and 120 respectively |
| Answer» C. 1, 120 and 120 respectively | |
| 1628. |
The properties of FETs closely resemble those of a |
| A. | thermionic valve |
| B. | P-N-P transistor |
| C. | N-P-N transistor |
| D. | UJT |
| Answer» B. P-N-P transistor | |
| 1629. |
Symbol shown in figure represents a |
| A. | P-channel enhancement MOSFET |
| B. | N-channel DEMOSFET |
| C. | UJT with P-type base |
| D. | UJT with N-type base |
| Answer» B. N-channel DEMOSFET | |
| 1630. |
Primary advantage of a crystal oscillator is that |
| A. | it can oscillate at any frequency |
| B. | it gives a high O/P voltage |
| C. | its frequency of oscillation remains almost constant |
| D. | it operates on a very low dc supply voltage |
| Answer» D. it operates on a very low dc supply voltage | |
| 1631. |
Transformer coupling is mostly used in |
| A. | RF amplifier |
| B. | audio amplifier |
| C. | both audio and RF amplifier |
| D. | none of the above |
| Answer» D. none of the above | |
| 1632. |
Which of the following statement about JFET is correct? |
| A. | In an N-channel JFET, the channel is the narrowest under zero gate bias condition |
| B. | In a JFET the gates are always forward biased |
| C. | In a JFET, gate-source cut off voltage is numerically equal to the pinch off voltage |
| D. | It is a voltage controlled device |
| Answer» D. It is a voltage controlled device | |
| 1633. |
The source of the harmonic distortion in a RC coupled transistor amplifier is usually |
| A. | power supply |
| B. | capacitor |
| C. | R-C circuit |
| D. | transistor |
| Answer» E. | |
| 1634. |
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 | |
| 1635. |
In figure, the function of resistor R is |
| A. | to reduce ripples in the output |
| B. | to improve voltage regulation |
| C. | to limit the surge current |
| D. | either (a) or (c) |
| Answer» D. either (a) or (c) | |
| 1636. |
Which of the following compensation method in amplifier can be used to reduce the bandwidth? |
| A. | Pole-zero compensation |
| B. | Dominant pole compensation |
| C. | Lead compensation |
| D. | Any of the above |
| Answer» C. Lead compensation | |
| 1637. |
Which circuit has its output signal from, the emitter? |
| A. | Common base |
| B. | Common emitter |
| C. | Emitter follower |
| D. | None of the above |
| Answer» D. None of the above | |
| 1638. |
A Colpitt's oscillator uses |
| A. | a tapped inductor |
| B. | an inductor and two capacitors |
| C. | both (a) and (b) |
| D. | either (a) or (b) |
| Answer» D. either (a) or (b) | |
| 1639. |
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 | |
| 1640. |
The gain of a source follower is unity. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 1641. |
The horizontal intercept of dc load line is the same as ideal |
| A. | cut off point |
| B. | saturation point |
| C. | operating point |
| D. | quasi saturation point |
| Answer» B. saturation point | |
| 1642. |
In an op-amp comparator, the positive or negative output is |
| A. | saturated |
| B. | amplifier |
| C. | unsaturated |
| D. | any of the above |
| Answer» B. amplifier | |
| 1643. |
In a 4 input OR gate, the total number of High outputs for the 16 input states are |
| A. | 16 |
| B. | 15 |
| C. | 14 |
| D. | 13 |
| Answer» C. 14 | |
| 1644. |
What will be output for decimal input 82? |
| A. | 0.82 V |
| B. | 8 V |
| C. | 0.1 V |
| D. | 10 mV |
| Answer» B. 8 V | |
| 1645. |
In oscillator circuits the energy feedback to its input terminal from output is |
| A. | always in phase with the input signal |
| B. | 90 out of phase with the input signal |
| C. | 180 out of phase with the input signal |
| D. | 270 out of phase with the input signal |
| Answer» D. 270 out of phase with the input signal | |
| 1646. |
In figure, current gain is |
| A. | <span class="symbol">a</span> |
| B. | <i>r</i> |
| C. | <sub><i>e</i></sub> |
| D. | <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/321-312-1.png"> |
| E. | <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/321-312-2.png"> |
| Answer» B. <i>r</i> | |
| 1647. |
In the CE circuit shown in figure the slope of dc load line will be |
| A. | <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/309-129-2.png"> |
| B. | <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/309-129-3.png"> |
| C. | <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/309-129-4.png"> |
| D. | <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/309-129-5.png"> |
| Answer» B. <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/309-129-3.png"> | |
| 1648. |
Which of the following values represents the open loop gain of typical op-amp? |
| A. | 100 |
| B. | 10000 |
| C. | 100000 |
| D. | 1000000 |
| Answer» D. 1000000 | |
| 1649. |
Efficiency of class A power amplifier is very poor. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 1650. |
If the value of C2 and C3 are doubled, the oscillation frequency will be |
| A. | quadrupled |
| B. | doubled |
| C. | unchanged |
| D. | halved |
| Answer» D. halved | |