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.
| 1551. |
The time constant of the circuit after the switch shown in the figure is opened is |
| A. | 0.2 s |
| B. | 5 s |
| C. | 0.1 s |
| D. | dependent on R and hence cannot be determined unless R is known |
| Answer» B. 5 s | |
| 1552. |
Assertion (A): In an R-L circuit having low resistance, current lags the voltage by nearly 90°.Reason (R): Power factor of a series RL circuit is R/Z. |
| 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 | |
| 1553. |
In an ac circuit, the maximum and minimum values of power factor can be |
| A. | 2 and 0 |
| B. | 1 and 0 |
| C. | 0 and -1 |
| D. | 1 and -1 |
| Answer» C. 0 and -1 | |
| 1554. |
Which of the following is/are correct? The circuit shown in the figure.is reciprocalhas Z11 = 2, Z22 = 2has Z11 = 4, Z22 = 2has Z11 = 0, Z22 = 2 Select the correct answer using the code given below: |
| A. | 1 and 3 |
| B. | 1 and 2 |
| C. | 1 and 4 |
| D. | 3 only |
| Answer» B. 1 and 2 | |
| 1555. |
The Laplace transform of a function is The function is |
| A. | E sin at |
| B. | Ee-at |
| C. | 1/(s + a) |
| D. | E cos at |
| Answer» D. E cos at | |
| 1556. |
If sequence currents Ia1 = 2 ∠- 90°, Ia2 = 0.2 ∠ 90° and Ia3 = 1.8 ∠ 90°, Ia = |
| A. | 0 |
| B. | 1 |
| C. | 4 |
| D. | 8 |
| Answer» D. 8 | |
| 1557. |
Consider the following units sec-1rad2/sec2secΩ The units of , RC and are respectively |
| A. | 1, 2, 4, 3 |
| B. | 3, 2, 1, 4 |
| C. | 2, 4, 1, 3 |
| D. | 1, 2, 3, 4 |
| Answer» E. | |
| 1558. |
For a symmetrical network |
| A. | z11 = z22 |
| B. | z12 = z21 |
| C. | z11 z22 and z12 = z21 |
| D. | z11 z12 - z122 = 0 |
| Answer» D. z11 z12 - z122 = 0 | |
| 1559. |
For the circuit shown in the figure, the current I is |
| A. | indeterminate due to indeterminate data |
| B. | zero |
| C. | 4 Amp |
| D. | 8 Amp |
| Answer» B. zero | |
| 1560. |
If absolute potential of A is - 8 V and that of B is - 16 V, VAB is equal to |
| A. | 24 V |
| B. | 8 V |
| C. | - 8 V |
| D. | - 24 V |
| Answer» C. - 8 V | |
| 1561. |
If Va1, Va2, Va0 are the symmetrical components of Va, then |
| A. | Va = Va1 + Va2 + Va0 |
| B. | Va = a2Va1 + aVa2 + Va0 |
| C. | Va = aVa1 + a2Va2 + Va0 |
| D. | Va = aVa0 + a2Va1 + Va2 |
| Answer» C. Va = aVa1 + a2Va2 + Va0 | |
| 1562. |
A system has transfer function The dc gain is |
| A. | 1 |
| B. | 2 |
| C. | 5 |
| D. | 10 |
| Answer» D. 10 | |
| 1563. |
In active filters inductances are divided because they |
| A. | are always associated with same resistance |
| B. | are bulky and unsuitable for miniaturization |
| C. | are non linear |
| D. | saturate quickly |
| Answer» C. are non linear | |
| 1564. |
In figure, the current supplied by battery immediately after switching on the circuit is |
| A. | 0.041666666666667 |
| B. | 0.16666666666667 |
| C. | 0.41666666666667 |
| D. | 0 |
| Answer» B. 0.16666666666667 | |
| 1565. |
In figure, the total power consumed is |
| A. | 10 W |
| B. | 12 W |
| C. | 16 W |
| D. | 20 W |
| Answer» B. 12 W | |
| 1566. |
The phase difference (jω - p1 ) |
| A. | phasor directed from p1 to jω |
| B. | phasor directed from origin to p1 |
| C. | phasor directed from origin to jω point |
| D. | phasor directed from jω to p1 |
| Answer» B. phasor directed from origin to p1 | |
| 1567. |
The polarities of the magnetised iron rod of are |
| A. | A is N, B is S and C is neutral |
| B. | A is N, B is S and C is S |
| C. | A is N, B is N and C is S |
| D. | A is S, N is S and C is N |
| Answer» D. A is S, N is S and C is N | |
| 1568. |
A system function the resonant frequency in rad/sec and bandwidth in rad/sec. is given by |
| A. | 10 and 1 |
| B. | 10, 4 |
| C. | 100, 5 |
| D. | 10, 10 |
| Answer» C. 100, 5 | |
| 1569. |
If L [f(t)] = F(s), Lf(t - T) |
| A. | esTF(s) |
| B. | e-sTF(s) |
| C. | F(s) - e-sT |
| D. | F(s) + e-sT |
| Answer» C. F(s) - e-sT | |
| 1570. |
In the circuit of figure the voltage across capacitor when switch is closed at t = ‚àû is |
| A. | 0 V |
| B. | 20 V |
| C. | very large |
| D. | 7.5 V |
| Answer» E. | |
| 1571. |
A capacitor used for power factor correction is single phase circuit decreases |
| A. | power factor |
| B. | line current |
| C. | both line current and p.f. |
| D. | the line current and increases p.f. |
| Answer» E. | |
| 1572. |
Which one is correct option? A pure capacitor never dissipates energy, but only stores.Capacitor can store finite amount of energy even cunent is zero.The current through a capacitor is zero if voltage across it d.c.Voltage across a capacitor cannot change instantaneously since it would require an infinite current.qc(0-) = qc(0+) |
| A. | 5, 4, 3, 2 |
| B. | 3, 4, 1, 2 |
| C. | 2, 4, 3, 1 |
| D. | 1, 2, 3, 4, 5 |
| Answer» E. | |
| 1573. |
A 20 Ω resistor, a 1H inductor and 1μF capacitor are connected in parallel the combination is driven by a unit step current. Under the steady state, source current flows through |
| A. | inductor |
| B. | capacitor |
| C. | resistor |
| D. | all |
| Answer» B. capacitor | |
| 1574. |
The electrolyte in a dry cell is completely dry. |
| A. | 1 |
| B. | |
| C. | 1000 Hz |
| D. | 4000 Hz |
| Answer» C. 1000 Hz | |
| 1575. |
A current of 1 A in the coil of an iron cored electromagnet cause a flux density of 0.2.T. If the current is 2 A, B= |
| A. | 0.2 T |
| B. | 0.4 T |
| C. | 0.4 T or less |
| D. | 0.4 T or more |
| Answer» C. 0.4 T or less | |
| 1576. |
The series element of a band stop filter is |
| A. | capacitive |
| B. | inductive |
| C. | parallel combination of L and C |
| D. | series combination of L and C |
| Answer» D. series combination of L and C | |
| 1577. |
Millman's theorem is the best to find |
| A. | equivalent voltage or current source |
| B. | equivalent voltage source |
| C. | equivalent voltage and resistance of a circuit |
| D. | none of the above |
| Answer» B. equivalent voltage source | |
| 1578. |
A two branch parallel tuned circuit has a coil of resistance 100 Ω and inductance 0.005 H in one branch and 10 nF capacitor in the second branch. At resonance frequency, the dynamic resistance is |
| A. | 1 Ω |
| B. | 10 Ω |
| C. | 100 Ω |
| D. | more than 100 Ω |
| Answer» E. | |
| 1579. |
The circuit shown in figure is a |
| A. | low pass filter |
| B. | high pass filter |
| C. | band pass filter |
| D. | band stop filter |
| Answer» B. high pass filter | |
| 1580. |
The switch in figure is initially closed. At t = 0 the switch is opened. At t = 0+, the current through R is |
| A. | I |
| B. | 0 |
| C. | Ie-t/RC |
| Answer» C. Ie-t/RC | |
| 1581. |
The sum of positive real function is positive real. |
| A. | 1 |
| B. | |
| C. | Both A and R are true and R is correct explanation of A |
| D. | Both A and R are true and R is not the correct explanation of A |
| Answer» B. | |
| 1582. |
In figure the total inductance of the circuit is |
| A. | L1 + L2 |
| B. | L1 + L2 + M |
| C. | L1 + L2 + 2M |
| D. | L1 + L2 + M |
| Answer» D. L1 + L2 + M | |
| 1583. |
For 2 port reciprocal network, o.c. output voltage divided by input current is equal to |
| A. | B |
| B. | z12 |
| C. | 1/y12 |
| D. | h12 |
| Answer» D. h12 | |
| 1584. |
Consider the following statements associated with two port networks. Z12 = Z21Y12 = Y21h12 = h21AD - BC = 1 Which one of the statement given above are correct? |
| A. | 1, 2, 3 |
| B. | 2, 3, 4 |
| C. | 1, 3, 4 |
| D. | 1, 2, 4 |
| Answer» E. | |
| 1585. |
The two conductors of a single phase transmission line suspended in air carry currents in opposite directions. The force per unit length on each conductor varies |
| A. | directly as the current in either conductor |
| B. | directly as the distance between the two conductors |
| C. | directly as the square of the current in either conductor |
| D. | inversely as the square of the distance between the two conductors |
| Answer» D. inversely as the square of the distance between the two conductors | |
| 1586. |
In an R-C series circuit excited by a voltage E, the charge across capacitor at t = 0+ is |
| A. | 0 |
| B. | CE |
| C. | CE (1 - e-t/RC) |
| D. | none of the above |
| Answer» B. CE | |
| 1587. |
In a series R, L, C circuit the impedance triangle is the same when XL < XC and XL > XC . |
| A. | 1 |
| B. | |
| Answer» C. | |
| 1588. |
A coil with large distributed capacitance has a |
| A. | high resonant frequency |
| B. | low resonant frequency |
| C. | low quality factor |
| D. | low resistance |
| Answer» B. low resonant frequency | |
| 1589. |
If V = 4 in the figure, the value of Is is given by |
| A. | 0.25 |
| B. | 5/2 A |
| C. | 0 |
| D. | none |
| Answer» B. 5/2 A | |
| 1590. |
The electrical energy required to heat a bucket of water to a certain temperature is 2 kWh. If heat losses, are 25%, the energy input is |
| A. | 2.67 kWh |
| B. | 3 kWh |
| C. | 2.5 kWh |
| D. | 3.5 kWh |
| Answer» B. 3 kWh | |
| 1591. |
A current wave is i = 100e-60t The initial and final values of current are |
| A. | 100 and 50 |
| B. | 100 and 0 |
| C. | 0 and 100 |
| D. | 100 and 100 |
| Answer» C. 0 and 100 | |
| 1592. |
An RLC series circuit has Q = 100 and ω0 = 20 rad/sec. The bandwidth is |
| A. | 0.2 rad/sec |
| B. | 2 rad/sec |
| C. | 20 rad/sec |
| D. | 2000 rad/sec |
| Answer» B. 2 rad/sec | |
| 1593. |
In the circuit shown in given figure, the values of i(0+) and I(‚àû), will be respectively |
| A. | zero and 1.5 A |
| B. | 1.5 A and 3 A |
| C. | 3 A and zero |
| D. | 3 A and 1.5 A |
| Answer» D. 3 A and 1.5 A | |
| 1594. |
A loudspeaker transformer has a turns ratio of 20 : 1. The speaker impedance is 20Ω. Primary impedance of transformer is |
| A. | 10 K |
| B. | 8 K |
| C. | 20 K |
| D. | 0.5 K |
| Answer» C. 20 K | |
| 1595. |
In a purely inductive ac circuit, the supply voltage and voltage induced across inductance are equal and opposite at all instants. |
| A. | 1 |
| B. | |
| C. | 1 |
| D. | |
| Answer» B. | |
| 1596. |
When slider of the potentiometer AB is in the position shown in figure, what resistance reading would be indicated by an ohmmeter connected between A and C? |
| A. | zero |
| B. | infinite |
| C. | can't say |
| D. | none of the above |
| Answer» B. infinite | |
| 1597. |
The current in an RL series circuit is 1 - e-t amperes. Then di/dt is |
| A. | 1 - e-t |
| B. | #NAME? |
| C. | et |
| D. | e-2t |
| Answer» D. e-2t | |
| 1598. |
A parallel RLC network has R = 4Ω, L = 4H, C = 0.25F. Then at resonance Q = |
| A. | 1 |
| B. | 10 |
| C. | 20 |
| D. | 40 |
| Answer» B. 10 | |
| 1599. |
If Y(s) = 1 + s, the network has |
| A. | 1 Ω resistor and 1 F capacitor in series |
| B. | 1 Ω resistor and 1 F capacitor in parallel |
| C. | 1 Ω resistor and 1 H inductor in series |
| D. | 1 Ω resistor and 1 H inductor in parallel |
| Answer» C. 1 Œ© resistor and 1 H inductor in series | |
| 1600. |
In an LC immittance H (s) |
| A. | the slope of dH (jω)/dω is always negative |
| B. | the slope of dH (jω)/dω is always positive |
| C. | the slope of dH (jω)/dω may be positive or negative |
| D. | the slope of dH (jω)/dω is constant |
| Answer» C. the slope of dH (jœâ)/dœâ may be positive or negative | |