MCQOPTIONS
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MCQOPTIONS
This section includes 1800 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics & Communication Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1501. |
If operator 'a' = 1 ∠120° then (1 + a2) = |
| A. | 3 |
| B. | 3 ∠30° |
| C. | 3 ∠ - 30° |
| D. | 3 ∠60° |
| Answer» B. 3 ‚à†30¬∞ | |
| 1502. |
The flux linkage ψ, self inductance L and current i are related as |
| A. | ψ = L/i |
| B. | ψ = Li |
| C. | ψ = Li2 |
| Answer» D. | |
| 1503. |
The transfer function of an R-L-C circuit given by The Quality factor (Q-factor) of this circuit is |
| A. | 25 |
| B. | 100 |
| C. | 50 |
| D. | 5000 |
| Answer» D. 5000 | |
| 1504. |
In a Parallel connection of circuit the bandwidth in terms of R, L, C is |
| A. | B = 1/RC |
| B. | B = 1/RL |
| C. | B = 1/RLC |
| D. | B = RLC |
| Answer» B. B = 1/RL | |
| 1505. |
In a practical voltage source, the terminal voltage |
| A. | cannot be less than source voltage |
| B. | cannot be higher than source voltage |
| C. | is always less than source voltage |
| D. | is always equal to source voltage |
| Answer» C. is always less than source voltage | |
| 1506. |
In figure, the current through R, after the steady state condition is reached, is |
| A. | I |
| B. | 0 |
| C. | |
| Answer» B. 0 | |
| 1507. |
The impedance of an RC series circuit is 12 Ω at f= 50 Hz. At f= 200 Hz, the impedance will be |
| A. | more than 12 |
| B. | less than 3 |
| C. | more than 3 Ω but less than 12 Ω |
| D. | more than 12 Ω but less than 24 Ω |
| Answer» D. more than 12 Œ© but less than 24 Œ© | |
| 1508. |
If the network in figure (1), (2) are equivalent at terminals A - B, then voltage V and resistance R are |
| A. | 100V and 12 Ω |
| B. | 60V and 12 Ω |
| C. | 100V and 30 Ω |
| D. | 60V and 30 Ω |
| Answer» D. 60V and 30 Œ© | |
| 1509. |
In figure, the current I |
| A. | is 2 A from A to B |
| B. | is 2 A from B to A |
| C. | depends on the value of R |
| D. | none of the above |
| Answer» D. none of the above | |
| 1510. |
A thermistor is used for |
| A. | over voltage protection |
| B. | temperature alarm circuit |
| C. | automatic light control |
| D. | none of the above |
| Answer» C. automatic light control | |
| 1511. |
In a series resonant circuit, the resonant frequency is |
| A. | geometric mean of half power frequencies |
| B. | arithmetic mean of half power frequencies |
| C. | difference of half power frequencies |
| D. | none of the above |
| Answer» B. arithmetic mean of half power frequencies | |
| 1512. |
The voltage of the source in circuit shown __________ if i(t) = - 20e-2t is |
| A. | 46.6 e-2t |
| B. | 47 e-2t |
| C. | 50 e-2t |
| D. | 0 |
| Answer» B. 47 e-2t | |
| 1513. |
For the circuit in figure, fed by a unit step voltage, vc = |
| A. | 1 - e-t/RC |
| B. | e-t/RC |
| C. | et/RC |
| D. | 1 |
| Answer» B. e-t/RC | |
| 1514. |
In the circuit of figure the current through 3 Ω resistance at t = ∞ is |
| A. | 0.16666666666667 |
| B. | 2.5 A |
| C. | 3.1 A |
| D. | 0 |
| Answer» C. 3.1 A | |
| 1515. |
A dc voltage source is connected across a series RLC circuit, Under steady state conditions, the applied dc voltage drops entirely across the |
| A. | R only |
| B. | C only |
| C. | L only |
| D. | R and L |
| Answer» C. L only | |
| 1516. |
An RL impedance function can also be realized as |
| A. | RC impedance function |
| B. | RC admittance function |
| C. | LC impedance function |
| D. | LC admittance function |
| Answer» C. LC impedance function | |
| 1517. |
When cells are connected in series, emfs of all cells must be equal. |
| A. | 1 |
| B. | |
| C. | Transistor |
| D. | Heater coil |
| Answer» C. Transistor | |
| 1518. |
In carbon resistor colour code, the fourth band indicates tolerance. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 1519. |
The voltage of single phase supply to residential consumers in India is |
| A. | 400 V |
| B. | 230 V |
| C. | 2.2 kV |
| D. | 11 kV |
| Answer» C. 2.2 kV | |
| 1520. |
The current wave of figure, is passed through a 3 H inductor during the period 0 to 2 seconds |
| A. | is 3 V |
| B. | is 6 V |
| C. | increases from 0 at t = 0 to 6 V at t = 2 seconds |
| D. | increases from 0 at t = 0 to 6 V at t = 2 seconds and then decreases |
| Answer» C. increases from 0 at t = 0 to 6 V at t = 2 seconds | |
| 1521. |
According to initial value theorem which one is correct |
| A. | 1, 4 |
| B. | 2, 3 |
| C. | 4, 2 |
| D. | 1, 2 |
| Answer» E. | |
| 1522. |
In figure, a voltmeter of internal resistance 1200 Ω is connected across 600 Ω resistance and it reads 5 V. The value of R is |
| A. | 1200 Ω |
| B. | 2400 Ω |
| C. | 3600 Ω |
| D. | 7200 Ω |
| Answer» C. 3600 Œ© | |
| 1523. |
A step voltage E is applied to an R-L series circuit. At t = 0, the current in the circuit is |
| A. | E/R |
| B. | E/L |
| C. | infinity |
| D. | zero |
| Answer» E. | |
| 1524. |
In an R-L-C circuit, v(t) = 20 sin (314 t + 5 p/6) and i(t) = 10 sin (314 t + 2p/3). The p.f of the circuit is |
| A. | 0.5 lead |
| B. | 0.866 lag |
| C. | 0.866 lead |
| D. | 0.5 lead |
| Answer» C. 0.866 lead | |
| 1525. |
In a series RLC high Q circuit the current peaks at a frequency. |
| A. | equal to the resonant frequency |
| B. | greater than the resonant frequency |
| C. | less than the resonant frequency |
| D. | none |
| Answer» B. greater than the resonant frequency | |
| 1526. |
Poor power factor |
| A. | reduces load handling capability of electrical system |
| B. | results in more power losses in the electrical system |
| C. | overloads alternators, transformers and distribution lines |
| D. | all |
| Answer» E. | |
| 1527. |
In the circuit of figure the current through 5 Ω resistance at t = 0+ is |
| A. | 0 |
| B. | 0.41666666666667 |
| C. | 6.67 A |
| D. | 5.1 A |
| Answer» D. 5.1 A | |
| 1528. |
Two coils X and Y have self inductances of 5 mH and 10 mH and mutual inductance of 3 mH. If the current in coils X change at a steady rate of 100 A/s, the emf induced in coil Y is |
| A. | 0.3 V |
| B. | 0.5 V |
| C. | 1 V |
| D. | 1.5 V |
| Answer» B. 0.5 V | |
| 1529. |
Energy = voltage x charge. |
| A. | 1 |
| B. | |
| C. | 5 mH |
| D. | 10 mH |
| Answer» B. | |
| 1530. |
The resistance of human body is about |
| A. | 5000 Ω |
| B. | 2000 Ω |
| C. | 1000 Ω |
| D. | 200 Ω |
| Answer» D. 200 Œ© | |
| 1531. |
Assertion (A): In series R-L-C circuit, the current may lead or lag the voltage depending on the value of R.Reason (R): Phase angle of an R-L series circuit is tan-1 (ωL/R). |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true and R is not the correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» E. | |
| 1532. |
For an m-derived high pass filter |
| A. | 1 |
| B. | |
| Answer» B. | |
| 1533. |
An RC impadence function has a pole at s = 0. The first element in the Foster form of synthesis |
| A. | is R |
| B. | may be R and C |
| C. | is C |
| D. | is R and C in parallel |
| Answer» C. is C | |
| 1534. |
A network has two sources of different frequencies. The only method of analysis which can be used to find current and voltages of different branches is the use of |
| A. | Kirchoff's laws |
| B. | Superposition theorem |
| C. | Thevenin's theorem |
| D. | Tellegen's theorem |
| Answer» C. Thevenin's theorem | |
| 1535. |
The impedance of a coil above self-resonant frequency is |
| A. | inductive |
| B. | capacitive |
| C. | resistive |
| D. | none |
| Answer» E. | |
| 1536. |
Which synthesis procedure requires the use of mutual inductance? |
| A. | Foster's synthesis |
| B. | Cauer synthesis |
| C. | Bott-Duffin synthesis |
| D. | Brune's synthesis |
| Answer» E. | |
| 1537. |
An RLC series circuit has R = 30 Ω, XL = 30 Ω and XC = 30 W. Its impedance is |
| A. | 30 ∠0°. |
| B. | 30 ∠45° |
| C. | 42.42 ∠45° |
| D. | 90 ∠45°. |
| Answer» B. 30 ‚à†45¬∞ | |
| 1538. |
The inverse Fourier transform of is |
| A. | sin ωt |
| B. | cos ωt |
| C. | sgn (t) |
| D. | u (t) |
| Answer» D. u (t) | |
| 1539. |
The current I flowing in the branch is |
| A. | -12 A |
| B. | 0 |
| C. | 0.125 |
| D. | -3 A |
| Answer» B. 0 | |
| 1540. |
To find current in a resistance connected in a network, Thevenin's theorem is used VTH = 20 V and RTH = 5 Ω. The current through the resistance |
| A. | is 4 A |
| B. | is 4 A or less |
| C. | is less than 4 A |
| D. | may be 4 A or less or more than 4 A |
| Answer» D. may be 4 A or less or more than 4 A | |
| 1541. |
In figure, the magnitude of V |
| A. | must be more than that of Va |
| B. | must be more than that of Vb |
| C. | must be more than that of Va or Vb |
| D. | can be equal to or less than or more than that of Va or Vb |
| Answer» E. | |
| 1542. |
Assertion (A): Energy stored in inductance is and that in capacitance is Reason (R): Inductance and capacitance are dual of each other. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true and R is not the correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» B. Both A and R are true and R is not the correct explanation of A | |
| 1543. |
The superposition theorem is applicable to |
| A. | linear, non-linear and time variant responses |
| B. | linear and non-linear resistors only |
| C. | linear responses only |
| D. | none of the above |
| Answer» D. none of the above | |
| 1544. |
For a series circuit of R and variable XL the admittance locus is |
| A. | a semicircle in first quadrant |
| B. | a semicircle in fourth quadrant |
| C. | a straight line in first quadrant |
| D. | a straight line in fourth quadrant |
| Answer» C. a straight line in first quadrant | |
| 1545. |
An m derived low pass filter has fc = 1000 Hz and m = 0.6. This filter will have infinite attenuation at |
| A. | f = 1250 Hz |
| B. | all frequencies above 1000 Hz |
| C. | f = 1562.5 Hz |
| D. | f = 1666.67 Hz |
| Answer» B. all frequencies above 1000 Hz | |
| 1546. |
In the circuit shown in the given figure, V0 is given by |
| A. | |
| B. | |
| Answer» B. | |
| 1547. |
In an R-C circuit, the impedance is 40 Ω at a frequency of 100 Hz. At 200 Hz the impedance should be |
| A. | 40 Ω |
| B. | 80 Ω |
| C. | 20 Ω |
| D. | more than 20 Ω but less than 40 Ω |
| Answer» E. | |
| 1548. |
At very low frequencies a series R-C circuit behaves as almost purely __________ . |
| A. | resistive |
| B. | inductive |
| C. | capacitive |
| D. | none of the above |
| Answer» D. none of the above | |
| 1549. |
Assertion (A): The Laplace transform of a ramp is 1/s2.Reason (R): The integral of a unit step function gives an impulse function. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true and R is not the correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» D. A is false but R is true | |
| 1550. |
Figure shows an R-L circuit. The current is i = 1 - e-t. The rate of change of current at t = 1 second is |
| A. | 1 A/s |
| B. | 0.63 A/s |
| C. | 0.37 A/s |
| D. | 0 |
| Answer» D. 0 | |