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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.
| 1751. |
Parallel wire transmission line is an example of |
| A. | lumped network |
| B. | distributed |
| C. | depend upon I/P signal strength |
| D. | power I/P |
| Answer» C. depend upon I/P signal strength | |
| 1752. |
The resonant frequency of a series resonant circuit is |
| A. | arithmetic mean of half power frequencies |
| B. | independent of inductance of the circuit |
| C. | independent of capacitance of the circuit |
| D. | geometric mean of half power frequencies |
| Answer» E. | |
| 1753. |
The equivalent unit of joule is |
| A. | newton |
| B. | newton-meter |
| C. | newton-metre2 |
| D. | none of the above |
| Answer» C. newton-metre2 | |
| 1754. |
For an RC admittance function |
| A. | the lowest critical frequency is a zero |
| B. | the highest critical frequency is a pole |
| C. | the lowest critical frequency is zero and the highest critical frequency is a pole |
| D. | the lowest critical frequency is a pole |
| Answer» D. the lowest critical frequency is a pole | |
| 1755. |
In a conductor, voltage v, conductance G and charges q are related as |
| A. | |
| B. | |
| Answer» B. | |
| 1756. |
Three resistances of 15 Ω, 10 Ω and 3 Ω are connected in parallel. The overall resistance is |
| A. | less than 3 Ω |
| B. | between 15 and 10 Ω |
| C. | between 10 and 3 Ω |
| D. | more than 3 Ω |
| Answer» B. between 15 and 10 Œ© | |
| 1757. |
An R-L series circuit is excited by a voltage v(t). The circuit was initially relaxed. Which of the following sources of v(t) would cause maximum current at t = 0+? |
| A. | unit step |
| B. | unit impulse |
| C. | unit ramp |
| D. | unit step plus unit ramp |
| Answer» C. unit ramp | |
| 1758. |
As x is increased from - ‚àû to ‚àû, the function |
| A. | monotonically increases |
| B. | monotonically decreases |
| C. | increases to a maximum value and then decrease |
| D. | decreases to a minimum value and then increases |
| Answer» B. monotonically decreases | |
| 1759. |
An RLC series circuit is excited by a step voltage E. The initial current through L is i (0-). In the s domain circuit the element L will be replaced by |
| A. | an impedance sL. |
| B. | an impedance sL in series with current source i(0) |
| C. | an impedance sL in series with a voltage source |
| D. | an impedance sL in series with a voltage source Li(0-1). |
| Answer» E. | |
| 1760. |
In the circuit shown in figure, for different values of R, the values of V and I are given. Other elements remaining the same. when R = ∞, V = 5 volt R = 0, I = 2.5 AR = 3 Ω, the value of V is given by |
| A. | 1 V |
| B. | 2 V |
| C. | 3 V |
| D. | 5 V |
| Answer» D. 5 V | |
| 1761. |
Drift velocity of electrons is generally less than 1 mm/s. |
| A. | 1 |
| B. | |
| C. | Tellegen's theorem |
| D. | Reciprocity theorem |
| Answer» B. | |
| 1762. |
In the circuit shown, the steady state is reached with S open S is closed at t = 0, the current I in the 1 Ω resistor connected is to be determined at t = 0+ is given by |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 43528 |
| Answer» B. 2 | |
| 1763. |
In the circuit of figure the current through 5 Ω resistance at t = ∞ is |
| A. | 0.16666666666667 |
| B. | 2.5 A |
| C. | 3.1 A |
| D. | 0 |
| Answer» C. 3.1 A | |
| 1764. |
In the circuit of figure, the switch is closed at t = 0. At t = 0+ the current through C is |
| A. | 0.16666666666667 |
| B. | 2.5 A |
| C. | 3.1 A |
| D. | 0 |
| Answer» B. 2.5 A | |
| 1765. |
Assertion (A): The impedance of a series resonant circuit is minimum at resonance.Reason (R): Resonance condition implies unity power factor condition. |
| 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 | |
| 1766. |
A capacitor is considered to be completely charged in __________ time constant. |
| A. | one |
| B. | three |
| C. | five |
| D. | eight |
| Answer» D. eight | |
| 1767. |
Bandwidth will be |
| A. | a.b |
| B. | a + b |
| C. | a |
| D. | b |
| Answer» D. b | |
| 1768. |
In the circuit of figure |
| A. | Va would always lag Vb |
| B. | Va would always lead Vb |
| C. | Va and Vb can be in phase |
| D. | phase angle between Va and Vb would always be 90° |
| Answer» C. Va and Vb can be in phase | |
| 1769. |
In a minimum function |
| A. | the degree of numerator and denominator are equal |
| B. | the degree of numerator and denominator are unequal |
| C. | the degree of numerator is one more than degree of denominator |
| D. | the degree of numerator is one less than degree of denominator |
| Answer» B. the degree of numerator and denominator are unequal | |
| 1770. |
A dielectric does not have leakage current. |
| A. | 1 |
| B. | |
| C. | 1000 Hz |
| D. | 2000 Hz |
| Answer» C. 1000 Hz | |
| 1771. |
In the series circuit shown in figure, for series resonance, the value of the coupling coefficient, K will be |
| A. | 0.25 |
| B. | 0.5 |
| C. | 0.1 |
| D. | 1 |
| Answer» B. 0.5 | |
| 1772. |
Assertion (A): Laplace transform of f(t) = e-at sin ωt is Reason (R): If Laplace transform of f(t) is F(s), then Laplace transform of e-at f(t) is F(s + a). |
| 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» C. A is true but R is false | |
| 1773. |
A choke coil of resistance R and inductance L is shunted by capacitor C. The dynamic resistance is |
| A. | R/LC |
| B. | C/RL |
| C. | L/RC |
| D. | 1/RLC |
| Answer» D. 1/RLC | |
| 1774. |
Two phasors having rms values V1 and V2 which are added to give a phasor having rms value V3. V3 is maximum if phase angle between V1 and V2 is |
| A. | 90° |
| B. | 180° |
| C. | 270° |
| D. | 360° |
| Answer» E. | |
| 1775. |
A magnetic circuit has an iron length of 20 cm and air gap length 0.1 cm. If μr = 200 then |
| A. | mmf for iron and air gap are equal |
| B. | mmf for iron is much less than that for air gap |
| C. | mmf for iron is much more than that for air gap |
| D. | either (a) or (c) |
| Answer» B. mmf for iron is much less than that for air gap | |
| 1776. |
When a current source I is suddenly connected across a two terminal relaxed RC circuit at time t = 0, the voltage across the current source is shown in figure. The RC circuit is |
| A. | a series combination of R and C |
| B. | a parallel combination of R and C |
| C. | a series combination of R and parallel combination of R and C |
| D. | a pure capacitor |
| Answer» D. a pure capacitor | |
| 1777. |
The two port networks are connected in cascade, the combination is to be represented as a single two-Port network. The parameters of the network are obtained by multiplying the individual matrix |
| A. | z-parameter |
| B. | h-parameter |
| C. | y-parameter |
| D. | ABCD parameter |
| Answer» E. | |
| 1778. |
In an RL series circuit the inductance is 1H and current at an instant is 0.6 A. The energy stored in magnetic field is |
| A. | 0.36 J |
| B. | 0.18 J |
| C. | 0.09 J |
| D. | 0.03 J |
| Answer» C. 0.09 J | |
| 1779. |
C = (2) (energy)/V2 |
| A. | 1 |
| B. | |
| C. | 1 and 2 |
| D. | 1 and 3 |
| Answer» B. | |
| 1780. |
Three identical coils each having self inductance L are connected in series so that the fluxes of all the three are in the same direction. If mutual inductance between each pair of coils is M, the total inductance of the arrangement is |
| A. | 3 L + 9 M |
| B. | 1.5 L + 3 M |
| C. | 3 L + 3 M |
| D. | 3 L + 6 M |
| Answer» C. 3 L + 3 M | |
| 1781. |
A series RLC circuit is supplied from a variable frequency ac source. The resonant frequency is ω0. The voltage across C is maximum at a frequency |
| A. | equal to ω0 |
| B. | slightly less than ω0 |
| C. | slightly more than ω0 |
| D. | none of the above |
| Answer» C. slightly more than œâ0 | |
| 1782. |
Substitution theorem applies to |
| A. | Linear network |
| B. | Non linear network |
| C. | Linear time invariant network |
| D. | Any network |
| Answer» D. Any network | |
| 1783. |
An R-L series circuit has R = 5 Ω and L = .01 H. It is fed by ac 50 Hz supply. The rms current in the circuit is 5 A. The active power supplied by the source is |
| A. | 25 W |
| B. | 50 W |
| C. | 125 W |
| D. | 250 W |
| Answer» D. 250 W | |
| 1784. |
Which of the following is correct? |
| A. | Voltages across a capacitance can change instantaneously |
| B. | Voltages across a capacitance cannot change instantaneously |
| C. | Charge across a capacitance is always constant |
| D. | Charge across a capacitance can change instantaneously |
| Answer» C. Charge across a capacitance is always constant | |
| 1785. |
Which one is correct statement? Circuit is always openNetwork is always openCircuit is always closedNetwork is always closed |
| A. | 1, 2 |
| B. | 2, 3 |
| C. | 3, 4 |
| D. | 1, 4 |
| Answer» C. 3, 4 | |
| 1786. |
Consider the following expression for the driving point impedance It represent on LC circuitIt represent on RLC circuitIt has poles lying on the jω axisIt has a pole at infinite frequency and a zero at zero frequency. Which one fo 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 | |
| 1787. |
If P = 250 W and p.f. = 0.707 lagging, Q = |
| A. | 250 vars |
| B. | - 250 vars |
| C. | 176.7 vars |
| D. | - 176.75 vars |
| Answer» B. - 250 vars | |
| 1788. |
In figure, the value of R should be |
| A. | 12 Ω |
| B. | 6 Ω |
| C. | 3 Ω |
| D. | 1.5 Ω |
| Answer» C. 3 Œ© | |
| 1789. |
The rms value of wave in figure is |
| A. | about 95 V |
| B. | about 80 V |
| C. | about 50 V |
| D. | about 25 V |
| Answer» C. about 50 V | |
| 1790. |
When an ac circuit has sources of different frequencies, the only method of analysis is superposition theorem. |
| A. | 1 |
| B. | |
| C. | B = 1/RC |
| D. | B = 1/RL |
| Answer» B. | |
| 1791. |
Henry is equivalent to |
| A. | Volts/Ampere |
| B. | Weber/Volt |
| C. | Weber/Ampere |
| D. | Weber/Ampere2 |
| Answer» D. Weber/Ampere2 | |
| 1792. |
In the circuit shown in the given figure, switch k is closed at t = 0. The circuit was initially relaxed then which one of the following sources of v(t) will produce maximum current at t = 0+? |
| A. | Unit step |
| B. | Unit impulse |
| C. | Unit ramp |
| D. | Unit step plus unit ramp |
| Answer» C. Unit ramp | |
| 1793. |
The circuit in figure, is to be scaled to an impedance level of 5kΩ and resonant frequency of 5 x 106 rad/sec. The possible combination of R, L, C is |
| A. | 2.5Ω, 0.2 mH, 200 pF |
| B. | 5 kΩ, 0.2 mH, 200 pF |
| C. | 5 kΩ, 0.2 mH, 200 μF |
| D. | 5 kΩ, 0.1 mH, 0.4 μF |
| Answer» C. 5 kŒ©, 0.2 mH, 200 ŒºF | |
| 1794. |
A series RC circuit has R = 5 Ω and C = 10 μF. The current in the circuit is 5 sin 20000t. The applied voltage is |
| A. | 252 sin (20000t + 45°) |
| B. | 252 sin (20000t - 45°) |
| C. | 252 sin 20000t |
| D. | 252 sin (20000t - 90°) |
| Answer» C. 252 sin 20000t | |
| 1795. |
The relation AD - BC = 1 where A, B, C, D are transmission parameters of a network is valid for |
| A. | every network |
| B. | passive but not reciprocal network |
| C. | passive and reciprocal network |
| D. | both active and passive networks |
| Answer» D. both active and passive networks | |
| 1796. |
Fourier transform and F(jω) of a signal f(t) has the property |
| A. | F(jω) = F(-jω) |
| B. | F(jω) = -F(-jω) |
| C. | F(jω) = F*(jω) |
| D. | F(jω) = -F*(-jω) |
| Answer» C. F(jœâ) = F*(jœâ) | |
| 1797. |
The three sides of an admittance triangle denote |
| A. | G, B, Y |
| B. | R, X, Y |
| C. | G, B, Z |
| D. | (R, Y, Z) or (R, X, Z) |
| Answer» E. | |
| 1798. |
The number of electrons in motion at the instant of positive peak of a symmetrical ac wave is the same as that at the instant of negative peak. |
| A. | 1 |
| B. | |
| C. | I |
| D. | 0 |
| Answer» B. | |
| 1799. |
A sinusoidal voltage has peak to peak value of 100 V. The rms value is |
| A. | 50 V |
| B. | 70.7 V |
| C. | 35.35 V |
| D. | 141.41 V |
| Answer» D. 141.41 V | |
| 1800. |
In a parallel resonant circuit, the circuit current at resonance is maximum. |
| A. | 1 |
| B. | |
| C. | about 95 V |
| D. | about 80 V |
| Answer» C. about 95 V | |