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.
| 1401. |
If the p and T circuits in figure are equivalent, then R1, R2, R3 respectively are |
| A. | 9 Ω, 6 Ω, 6 Ω |
| B. | 6 Ω, 6 Ω, 9 Ω |
| C. | 9 Ω, 6 Ω, 9 Ω |
| D. | 6 Ω, 9 Ω, 6 Ω |
| Answer» C. 9 Œ©, 6 Œ©, 9 Œ© | |
| 1402. |
The reading of the voltmeter V in figure should be __________ volt. |
| A. | 60 |
| B. | 10 |
| C. | 66 |
| D. | 0 |
| Answer» C. 66 | |
| 1403. |
A series RL circuit is excited by a voltage v(t) = Vm sin (ωt + Φ). The transient current will be zero if |
| A. | Φ = 0 |
| B. | ω = 0 |
| C. | Φ = tan-1 (ωL/R) |
| D. | ω - tan-1 (ωL/R) = p/2 |
| Answer» D. œâ - tan-1 (œâL/R) = p/2 | |
| 1404. |
For H(s) to be positive real, the condition Re[H(jω)] ≥ 0 for 0 ≤ ω ≤ ∞ is |
| A. | a necessary condition |
| B. | a sufficient condition |
| C. | a necessary and sufficient condition |
| D. | is not a necessary condition |
| Answer» B. a sufficient condition | |
| 1405. |
A parallel ac circuit in resonance will |
| A. | act like a resistor of low value |
| B. | have a high impedance |
| C. | have current in each section equal to the line current |
| D. | have a high voltage developed across each inductive and capacitive section |
| Answer» C. have current in each section equal to the line current | |
| 1406. |
Resistivity of semiconductors is around 100 Ω-m. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 1407. |
A dependent source |
| A. | may be a current source or voltage source |
| B. | is neither a current source nor a voltage source |
| C. | is always a voltage source |
| D. | is always a current source |
| Answer» E. | |
| 1408. |
Which of the following theorems enables a number of voltage (or current) sources to be combined directly into a single voltage (or current) source? |
| A. | Superposition theorem |
| B. | Compensation theorem |
| C. | Millman's theorem |
| D. | Thevenin's theorem |
| Answer» D. Thevenin's theorem | |
| 1409. |
In figure V is ideal voltmeter having infinite resistance. It will read __________ volt. |
| A. | 40 |
| B. | 60 |
| C. | 0 |
| D. | 100 |
| Answer» B. 60 | |
| 1410. |
Two coupled coils with self inductances of 4 mH and 16 mH are connected in series. The maximum possible value of inductance can be |
| A. | 36 mH |
| B. | 20 mH |
| C. | 28 mH |
| D. | 64 mH |
| Answer» B. 20 mH | |
| 1411. |
In a series RLC circuit p.f is lagging when f < resonance frequency. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 1412. |
If the ratio p(s)/q(s) represents a transfer function then |
| A. | the degree of p(s) may be as small as zero, independent of degree of q(s) |
| B. | the degree of p(s) and q(s) must be equal |
| C. | the degrees of p(s) and q(s) must not be equal |
| D. | the degrees p(s) and q(s) must differ by at least two |
| Answer» B. the degree of p(s) and q(s) must be equal | |
| 1413. |
Which of the following is correct? The circuit shown in the figure. is reciprocal but not symmetricalis not reciprocal but symmetricalboth reciprocal and symmetricalneither reciprocal nor symmetrical |
| A. | 1, 2 and 3 |
| B. | 2, 3 and 4 |
| C. | 1, 3 and 4 |
| D. | 1, 2 and 4 |
| Answer» B. 2, 3 and 4 | |
| 1414. |
In solids the current flow is due to electrons only. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 1415. |
An RC series circuit has R = 20 Ω and XC = 20 Ω. Then Z = |
| A. | 40 Ω |
| B. | 28.28 Ω |
| C. | 20 Ω |
| D. | 1 Ω |
| Answer» C. 20 Œ© | |
| 1416. |
A series resonant circuit has parameters 10 ω, 1 H and 0.1 F. It is excited by a voltage v = 100 sin ωt. At resonant frequency, the power dissipated in the circuit is |
| A. | 1000 W |
| B. | 707 W |
| C. | 500 W |
| D. | 414.14 W |
| Answer» D. 414.14 W | |
| 1417. |
Which one of the following is an active component? |
| A. | Diode (p-n) |
| B. | Transistor as Amplifier |
| C. | Transformer |
| D. | Inductor |
| Answer» C. Transformer | |
| 1418. |
The time constant of an R.C. circuit increases if the value of resistance is |
| A. | increased |
| B. | decreased |
| C. | either of the above |
| D. | none of the above |
| Answer» B. decreased | |
| 1419. |
In the circuit of figure, the power consumed in resistance R is measured when one source is acting at one time. These values are 18 W, 50 W and 98 W. When all source act together the maximum and minimum power can be |
| A. | 98 W and 18 W |
| B. | 166 W and 18 W |
| C. | 450 W and 2 W |
| D. | 166 W and 2 W |
| Answer» C. 450 W and 2 W | |
| 1420. |
The hot resistance of a tungsten lame is about 12 times its cold resistance. Accordingly, the cold resistance of a 60 Ω, 120 V lamp is about __________ ohm. |
| A. | 5 |
| B. | 240 |
| C. | 2 |
| D. | 2880 |
| Answer» D. 2880 | |
| 1421. |
In a series circuit with XL constant and R variable the current locus lies in the third quadrant. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 1422. |
A second order system will have |
| A. | all resistances |
| B. | resistances and inductances |
| C. | resistances, inductance and capacitances |
| D. | either (b) or (c) |
| Answer» C. resistances, inductance and capacitances | |
| 1423. |
The voltage induced in a loop of wire rotating in a strong and steady magnetic field is |
| A. | pulsating dc |
| B. | dc |
| C. | rectified ac |
| D. | ac |
| Answer» E. | |
| 1424. |
The transfer function represents |
| A. | a high pass filter |
| B. | band elimination filter |
| C. | a resonator |
| D. | an all pass filter |
| Answer» B. band elimination filter | |
| 1425. |
Two passive elements are connected in series and a dc voltage is applied to the circuit. The time variation of the current is shown in figure. The two elements are |
| A. | one resistance and the other inductance |
| B. | both resistances |
| C. | one inductance and the other capacitance |
| D. | one resistance and the other capacitance |
| Answer» B. both resistances | |
| 1426. |
If a coil has diameter 'd' number of turns 'N' and form factor 'F' then the inductance of coil is proportional to |
| A. | N2dF |
| B. | Nd2F |
| Answer» C. | |
| 1427. |
The active elements on the positive and negative plates of lead acid battery are: |
| A. | lead peroxide and lead |
| B. | lead and lead peroxide |
| C. | lead peroxide and lead sulphate |
| D. | lead and lead |
| Answer» B. lead and lead peroxide | |
| 1428. |
An electrical network with 8 independent nodes will have __________ nodal equations. |
| A. | 4 |
| B. | 6 |
| C. | 7 |
| D. | 8 |
| Answer» D. 8 | |
| 1429. |
A series circuit has R = 5 Ω and C = 10 μF. It is switched on to a 12 V dc battery at t = 0. The current in the circuit will be maximum |
| A. | at t = RC |
| B. | at t = ‚àû |
| C. | at t = 0+ |
| D. | none of the above |
| Answer» D. none of the above | |
| 1430. |
RMS value is always higher than average value. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 1431. |
With Is disconnected I = - 1, when Is = b is connected, the value of I will become |
| A. | 0.083333333333333 |
| B. | -1 A |
| C. | 0.041666666666667 |
| D. | 0.125 |
| Answer» D. 0.125 | |
| 1432. |
Assertion (A): Operator has a value 1 ∠ - 90° or 1 ∠ 90°.Reason (R): Operator 'a' has a value 1 ∠ 120°. |
| 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. | |
| 1433. |
If Δs is an element of area and ΔI is the current through this element, current density J is defined as |
| A. | J = ΔI/Δs |
| B. | |
| Answer» C. | |
| 1434. |
For the circuit shown in the figure, the time constant RC = 1 ms. The input voltage is V1(t) = 2 sin 103 t. The output voltage V0(t) is equal to |
| A. | sin (103 t - 45°) |
| B. | sin (103 t + 45°) |
| C. | sin (103 t - 53°) |
| D. | sin (103 t + 53°) |
| Answer» B. sin (103 t + 45¬∞) | |
| 1435. |
In figure, the current iL at t = ‚àû is |
| A. | I |
| B. | 0 |
| Answer» B. 0 | |
| 1436. |
Q of a coil increases with Q increasing frequencyvaries linearly with frequencyincrease with increasing frequency because R increases at high frequencydecrease after the peak frequency because R increases at H.F. the correct statements are |
| A. | A, B |
| B. | C, D |
| C. | A, C |
| D. | B, D |
| Answer» C. A, C | |
| 1437. |
If the transfer function has zeros only on jω axis or in left half plane, it is a minimum phase function. |
| A. | 1 |
| B. | |
| C. | golden |
| D. | silver |
| Answer» B. | |
| 1438. |
A system function is . The system is at rest for t < 0, i(t) = 2u(t) where u(t) is an unit step, V(t) for t > 0 is given by |
| A. | e-6t |
| B. | 2e+6t |
| C. | 2e-6t |
| D. | ‚àû |
| Answer» D. ‚àû | |
| 1439. |
When analysing two port networks in cascade, it is more convenient to use |
| A. | z parameters |
| B. | h parameters |
| C. | T parameters |
| D. | y parameters |
| Answer» D. y parameters | |
| 1440. |
Insulation resistance of a cable is directly proportional to its length. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 1441. |
For a given line voltage, four heating coils will produce maximum heat when connected |
| A. | all in parallel |
| B. | all in series |
| C. | with two parallel pairs in series |
| D. | one pair in parallel with the other two in series |
| Answer» B. all in series | |
| 1442. |
A phasor is |
| A. | a line representing the magnitude and direction of an alternating quantity |
| B. | a line which represents the magnitude and phase of an alternating quantity |
| C. | an instrument used for measuring phases of an unbalanced 3-phase load |
| D. | a coloured tag or band for distinguishing between different phases of a 3-phase supply |
| Answer» C. an instrument used for measuring phases of an unbalanced 3-phase load | |
| 1443. |
In a series ac circuit a voltage of 20 V at 25 Hz causes a current of 0.20 A, while the same voltage at 75 Hz causes a current of 0.12 A. The circuit consists of |
| A. | R and C in parallel |
| B. | R and C in series |
| C. | R and L in series |
| D. | either (a) or (b) |
| Answer» C. R and L in series | |
| 1444. |
Wave A = 100 sin ωt and wave B = 100 cos ωt. Then |
| A. | rms values of the two waves are equal |
| B. | rms values of A is more than that of B |
| C. | rms values of A is less than that of B |
| D. | rms values of the two waves may or may not be equal |
| Answer» B. rms values of A is more than that of B | |
| 1445. |
The function |
| A. | is a reactance function |
| B. | is an RC function |
| C. | is an RL function |
| D. | may be reactance function or RC function |
| Answer» B. is an RC function | |
| 1446. |
A two port network is said to be reciprocal if |
| A. | h12 = - h21 |
| B. | AD - BC = 1 |
| C. | y12 = y21 |
| D. | all |
| Answer» E. | |
| 1447. |
In the circuit shown in the figure, the current supplied by the sinusoidal current source I is |
| A. | 28 A |
| B. | 0.16666666666667 |
| C. | 20 A |
| D. | not determinable from the data given |
| Answer» D. not determinable from the data given | |
| 1448. |
v-i relation for a capacitor is |
| A. | 1 |
| B. | |
| C. | 6 sec |
| D. | 10 sec |
| Answer» B. | |
| 1449. |
The voltage drop per ampere-metre of an aluminium conductor is higher as compared to a copper conductor of the same size due to its higher |
| A. | insulation resistance |
| B. | resistivity |
| C. | conductivity |
| D. | current density |
| Answer» C. conductivity | |
| 1450. |
An RC driving point impedance function has zeros at s = - 2 and s = - 5. The admissible poles are |
| A. | s = 0 and s = -6 |
| B. | s = -1 and s = -3 |
| C. | s = 0 and s = -1 |
| D. | s = -3 and s = -4 |
| Answer» C. s = 0 and s = -1 | |