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.
| 551. |
If figure, power dissipated in 30Ω resistance will be maximum when value of R = |
| A. | 30 Ω |
| B. | 16 Ω |
| C. | 9 Ω |
| D. | zero |
| Answer» D. zero | |
| 552. |
A coil of resistance R and inductance L is connected in series with 5 μF capacitor. The source frequency is equal to resonance frequency and circuit current is 0.5 A. Another 5 F capacitor is connected in parallel with the above capacitor. The circuit current will be |
| A. | 0.5 A |
| B. | more than 0.5 A |
| C. | less than 0.5 A |
| D. | 0.5 A or less |
| Answer» D. 0.5 A or less | |
| 553. |
Two sinusoidal waves 1 and 2 have peak values Vm1 and Vm². Wave 1 is leading wave 2 by ∠θ. Which of the following is correct? |
| A. | v1 = Vm1 sin θ and v2 = Vm² cos θ |
| B. | v1 = Vm1 sin ωt and v2 = Vm² sin (ωt - θ) |
| C. | v1 = Vm1 sin (ωt + θ/2) and v2 = Vm² sin ωt |
| D. | none of the above |
| Answer» C. v1 = Vm1 sin (ωt + θ/2) and v2 = Vm² sin ωt | |
| 554. |
If V = 100 ∠ 16°, the √(V) is |
| A. | 10 ∠ 32° |
| B. | 10 ∠ 8° |
| C. | 10 ∠ 16° |
| D. | 10 ∠ 4° |
| Answer» C. 10 ∠ 16° | |
| 555. |
In a coupled coil the primary has 100 turns and secondary has 200 turns. The primary produces, a flux Φ = e^-t. The coefficient of coupling is 1. The voltages induced in secondary is |
| A. | 200 e^-t V |
| B. | 200 e^t V |
| C. | 200 V |
| D. | none of the above |
| Answer» B. 200 e^t V | |
| 556. |
Consider the following: Energy storage capability of basic passive elements is due to the fact that1. resistance dissipates energy2. capacitance stores energy3. inductance dissipates energy Which of the above is/are correct? |
| A. | 1, 2, and 3 |
| B. | 1 and 3 |
| C. | 3 only |
| D. | 1 and 2 |
| Answer» E. | |
| 557. |
Consider the following expression for the driving point impedance1. It represent on LC circuit2. It represent on RLC circuit3. It has poles lying on the jω axis4. It has a pole at infinite frequency and a zero at zero frequency.Which one of the statement given above are correct? |
| A. | 2 and 4 |
| B. | 1 and 3 |
| C. | 1 and 4 |
| D. | 2 and 3 |
| Answer» C. 1 and 4 | |
| 558. |
In a two terminals network the O.C. voltage measured at the given terminals is 100 V and s.c., currents at the same terminals 5 A. If a load of 80 Ω resistance is connected at the terminals, load current is |
| A. | 1 A |
| B. | 1.25 A |
| C. | 6 A |
| D. | 6.25 A |
| Answer» B. 1.25 A | |
| 559. |
In the circuit of figure the current through 5 Ω resistance at t = 0+ is |
| A. | 0 A |
| B. | 10 A |
| C. | 6.67 A |
| D. | 5.1 A |
| Answer» D. 5.1 A | |
| 560. |
When three 100 K, ± 10% fixed resistors of 1/4 W Power rating are connected in parallel, the resulting 33 K resistor will have a tolerance specification and power rating of |
| A. | ± 10% and 3/4 W respectively |
| B. | ± 10% and 1/12 W respectively |
| C. | ± 3.3.% and 3/4 W respectively |
| D. | ± 30% and 3/4 W respectively |
| Answer» B. ± 10% and 1/12 W respectively | |
| 561. |
The Thevenin's equivalent of network in figure(1) is a 10 V source in series with 2 Ω resistance. If a 3 Ω resistance is connected across AB as shown in figure(2) the Thevenin's equivalent is |
| A. | 10 V in series with 1.2 Ω resistance |
| B. | 6 V in series with 1.2 Ω resistance |
| C. | 10 V in series with 5 Ω resistance |
| D. | 6 V in series with 5 Ω resistance |
| Answer» C. 10 V in series with 5 Ω resistance | |
| 562. |
If operator 'a' = 1 ∠120° then (1 + a) = |
| A. | -a |
| B. | -a² |
| C. | √a |
| D. | -1 |
| Answer» C. √a | |
| 563. |
Three resistance of 15 Ω each are connected in delta. The resistance of equivalent star will have a value of |
| A. | 15 Ω |
| B. | 5 Ω |
| C. | 5/3 Ω |
| D. | 45 Ω |
| Answer» C. 5/3 Ω | |
| 564. |
In the circuit, Vs = 10 cos ωt, power drawn by the 4Ω resistor is 8 watt. The power factor is |
| A. | 1 |
| B. | 0.5 |
| C. | 0.85 |
| D. | 0 |
| Answer» D. 0 | |
| 565. |
In an infinite ladder Ckt as shown above each resistance of rΩ then RAB |
| A. | ∞ |
| B. | 4r/3 |
| C. | 1.61 Ω |
| D. | none |
| Answer» D. none | |
| 566. |
R, L and C are in parallel. The circuit is switched on to a constant current source I at t = 0. At t = ∞ the current through inductance is I. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» B. False | |
| 567. |
For the circuit of figure |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 568. |
A circuit has two branches in parallel and each branch has only one element. The applied voltage and source current are v = 200 sin (200t + 30°) and i = 50 sin (200t + 50°). If one branch has capacitor, the other branch contains |
| A. | resistance |
| B. | inductance |
| C. | capacitance |
| D. | resistance or capacitance |
| Answer» B. inductance | |
| 569. |
Two capacitors of 2 μF and 4 μF capacitance are connected in series across a 30 V dc battery. After the capacitors have been charged, the voltage across them will be |
| A. | 15 V each |
| B. | 10 V and 20 V |
| C. | 20 V and 10 V |
| D. | 30 V each |
| Answer» D. 30 V each | |
| 570. |
When a 10 K, 10%, 1/4 Ω resistor is connected in series with a 12 K, ± 1%, 1/4 Ω resistor, the resulting combination has the following specifications |
| A. | 22 K, ± 11%, 1/2 Ω |
| B. | 22 K, ± 5.5%, 1/2 Ω |
| C. | 22 K, ± 5.5%, 1/8 Ω |
| D. | none of these |
| Answer» C. 22 K, ± 5.5%, 1/8 Ω | |
| 571. |
KVL equation for the circuit of figure is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 572. |
The Laplace transform of a function f(t) u(t) is __________ where f(t) is periodic with period T, and y(S) times the L.T. of f(t) for first period. Then |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» E. | |
| 573. |
Two voltages are 50 ∠0 V and 75 ∠ - 60° V. The sum of these voltages is |
| A. | 109 ∠ - 60° V |
| B. | 109 ∠ - 25° V |
| C. | 109 ∠ - 36.6° V |
| D. | 100 ∠ - 50.1° V |
| Answer» D. 100 ∠ - 50.1° V | |
| 574. |
The condition on R, L and C such that the step response y(t) in the figure has no oscillation, is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 575. |
If operator 'a' = 1 ∠120° then (1 + a + a²) = |
| A. | -a |
| B. | -a² |
| C. | 1 |
| D. | 0 |
| Answer» E. | |
| 576. |
The time constant of the circuit in figure shown. |
| A. | RC |
| B. | RC/2 |
| C. | 1/2RC |
| D. | 2/RC |
| Answer» C. 1/2RC | |
| 577. |
A series RL circuit has Z(s) = 1/s+4 . If a voltage 4 sint + 4t is applied, the steady state current will be |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 578. |
In figure, the ratio V24/V23 is |
| A. | 1/3 |
| B. | 2/3 |
| C. | 3/4 |
| D. | 4/3 |
| Answer» B. 2/3 | |
| 579. |
The following table gives some Laplace transforms and the functions. f(t) F(s)1. δ(t) s2. u(t) 1/s3. tu(t) 2/s²4. t²u(t) 2s³Of these the correctly matched pairs are |
| A. | 2 and 4 |
| B. | 1 and 4 |
| C. | 2 and 4 |
| D. | 1 and 2 |
| Answer» E. | |
| 580. |
The final value of following equation is |
| A. | ∞ |
| B. | 2 |
| C. | 1 |
| D. | zero |
| Answer» D. zero | |
| 581. |
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 | |
| 582. |
For a network having 1 Ω resistor and 1 F capacitor in series Z(s) = |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 583. |
Choose the correct option (↔ dual). |
| A. | Tree ↔ cotree |
| B. | Twig ↔ Link |
| C. | Cutset ↔ Loop |
| D. | all |
| Answer» E. | |
| 584. |
Figure shows a dc circuit. The Thevenin's equivalent circuit at terminals a - b is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» E. | |
| 585. |
In the circuit of figure the voltage across capacitor when switch is closed at t = ∞ is |
| A. | 0 V |
| B. | 20 V |
| C. | very large |
| D. | 7.5 V |
| Answer» E. | |
| 586. |
An infinite ladder is constructed with 1 Ω and 2 Ω resistors shown below. |
| A. | 8.18 A |
| B. | 0 A |
| C. | 9 A |
| D. | can't determined |
| Answer» D. can't determined | |
| 587. |
For node 1 in figure, KCL equation is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 588. |
In the circuit of figure, the switch is closed at t = 0. At t = 0⁺ the current through C is |
| A. | 4 A |
| B. | 2.5 A |
| C. | 3.1 A |
| D. | 0 |
| Answer» B. 2.5 A | |
| 589. |
In figure, the capacitor is charged to 1 V. At t = 0 the switch is closed so that i = e^(-t). When i = 0.37 A, the voltage across capacitor is |
| A. | 1 V |
| B. | 0.63 V |
| C. | 0.37 V |
| D. | 0.185 V |
| Answer» D. 0.185 V | |
| 590. |
A system is at rest for t < 0. It is given by the following equation. If steady state is reached at t = 0, then the value of angle A is given by |
| A. | 0 |
| B. | 45 ° |
| C. | - 45° |
| D. | ∞ |
| Answer» C. - 45° | |
| 591. |
Consider the following statement: |
| 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. | |
| 592. |
In the circuit of figure the current through C at t = ∞ is |
| A. | 4 A |
| B. | 2.5 A |
| C. | 3.1 A |
| D. | 0 |
| Answer» E. | |
| 593. |
In figure |
| A. | Wave A is lagging wave B by ∠θ |
| B. | Wave A is leading wave B by ∠θ |
| C. | Wave A is lagging wave B by ∠θ and the two waves have same rms values |
| D. | Wave A is lagging wave B by ∠θ and the two waves have different rms values |
| Answer» C. Wave A is lagging wave B by ∠θ and the two waves have same rms values | |
| 594. |
In figure the voltage drop across the 10 Ω resistance is 10 V. The resistance R |
| A. | is 6 Ω |
| B. | is 8 Ω |
| C. | is 4 Ω |
| D. | cannot be found |
| Answer» B. is 8 Ω | |
| 595. |
The distance between the plates of a parallel plate capacitor is d. The dielectric is in two parts, each of equal thickness but dielectric constants ∈1 and ∈2 respectively. The total capacitance will be proportional to |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 596. |
An ideal transformer has a turn ratio of 2 : 1. Taking hv side as port 1 and lv side as port 2, transmission parameters of transformer are |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 597. |
For the network of figure KVL for first loop is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 598. |
In the circuit shown in given figure, the values of i(0+) and I(∞), 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 | |
| 599. |
Given Is = 20 A, Vs = 20 V, the current I in the 3 Ω resistance is given by |
| A. | 4 A |
| B. | 8 A |
| C. | 2 A |
| D. | 16 A |
| Answer» B. 8 A | |
| 600. |
A resistance R is connected to a voltage source Vs having internal resistance Rs. A voltmeter of resistance Rm is used to measure the voltage across R. The voltmeter will read |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» E. | |