Explore topic-wise MCQs in Engineering.

This section includes 9294 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering knowledge and support exam preparation. Choose a topic below to get started.

3351.

Energy = voltage x charge.

A. True
B. False
Answer» B. False
Discussion
3352.

If the diameter of a wire is doubled, the current carrying capacity of the wire becomes

A. half
B. twice
C. four times
D. one-fourth
Answer» D. one-fourth
Discussion
3353.

If an admittance Y(s) has a term Ks, the realization would give

A. an inductance of value K
B. a resistance of value K
C. a capacitance of value K
D. either (a) or(c)
Answer» B. a resistance of value K
Discussion
3354.

A coil is wound having a diameter d. Its inductance is 10 mH. If it is rewound on the same core with a wire having diameter 0.5 d and total weight of the wire is the same as before, the inductance will be

A. 5 mH
B. 10 mH
C. 160 mH
D. 40 mH
Answer» D. 40 mH
Discussion
3355.

A resistance and an inductance are connected in parallel and fed from 50 Hz ac mains. Each branch takes a current of 5 A. The current supplied by source is

A. 10 A
B. 7.07 A
C. 5 A
D. zero
Answer» C. 5 A
Discussion
3356.

Three inductors each 30 mH are connected in delta. The value of inductance or each arm of equivalent star is

A. 10 mH
B. 15 mH
C. 30 mH
D. 90 mH
Answer» B. 15 mH
Discussion
3357.

Which statement is true for an ac circuit?

A. Active power is always less than apparent power
B. Active power cannot be more than apparent power
C. Active power is always more than reactive power
D. Active power cannot be more than reactive power
Answer» C. Active power is always more than reactive power
Discussion
3358.

A square current wave of magnitude 1 A is applied to an element for 5 seconds. The voltage across the element rises linearly from 0 to final value linearly. The element is

A. resistance
B. inductance
C. capacitance
D. R and C in series
Answer» D. R and C in series
Discussion
3359.

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
Discussion
3360.

If the iron core of a coil is removed so that it becomes an air cored coil, its inductance

A. will increase
B. will decrease
C. will remain the same
D. may increase or decrease
Answer» C. will remain the same
Discussion
3361.

A periodic voltage v(t) = 1 + 4 sin t + 2 cos t is applied across a 1 ohm resistance. The power dissipated is

A. 1 W
B. 11 W
C. 21 W
D. 24.5 W
Answer» C. 21 W
Discussion
3362.

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
Discussion
3363.

In a series RLC circuit excited by e = Em sin t is seen that LC < 1/ 2. Then

A. I lags E
B. I leads E
C. I leads E are in phase
D. voltage across L and C are equal
Answer» C. I leads E are in phase
Discussion
3364.

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. <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/122-686-1.png">
B. <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/122-686-2.png">
C. <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/122-686-3.png">
D. <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/122-686-4.png">
Answer» E.
Discussion
3365.

When a lead acid battery is being charged, the specific gravity of the electrolyte

A. decreases
B. increases
C. either increases or decreases
D. remains the same
Answer» C. either increases or decreases
Discussion
3366.

In a tungsten filament lamp

A. the current at the instant of switching is less than operating current
B. the current at the instant of switching is more than operating current
C. the current at the instant of switching is equal to operating current
D. the current at the instant of switching may be less than or equal to operating current
Answer» E.
Discussion
3367.

Two similar mutually coupled coils have a total inductance of 900 mH and coefficient of coupling 0.5. The self inductance of each coils is

A. 300 mH
B. 150 mH
C. 75 mH
D. 50 mH
Answer» B. 150 mH
Discussion
3368.

Flux linkages and voltages v are related as

A. <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/106-430-1.png">
B. <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/106-430-2.png">
C. <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/106-430-3.png">
D. <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/106-430-4.png">
Answer» C. <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/106-430-3.png">
Discussion
3369.

The function of a choke in a fluorescent lamp is

A. at the time of starting only
B. during the working of time but not at starting time
C. both at the time of starting and during working
D. none of the above
Answer» D. none of the above
Discussion
3370.

A constant k low pass T section filter has a characteristic impedance of 600 p at zero frequency. At f = fc the characteristic impedance is

A. 600 &ohm;
B. zero
C. infinite
D. more than 600 ohms
Answer» C. infinite
Discussion
3371.

The switch in figure is initially closed. At t = 0 the switch is opened. At t = 0+, the current through inductance is

A. <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/101-337-2.png">
B. I
C. 0
D. <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/101-337-3.png">
Answer» D. <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/101-337-3.png">
Discussion
3372.

Bus bars are always meant for very heavy currents.

A. True
B. False
Answer» C.
Discussion
3373.

For a high pass filter attenuation = 0 at f = 0.

A. True
B. False
Answer» C.
Discussion
3374.

S is closed for a long time and steady state is reached. S is opened at t(0-). The voltage marked V is V0 at t = 0+ and Vf at t = . Then value of V0 and Vf are respectively

A. 8, 8
B. 0, 1
C. 4, 0
D. 4, 8
Answer» E.
Discussion
3375.

Current having waveform in figure flows through 10 &amp;ohm; resistance. Average power is

A. 1000 W
B. 500 W
C. 333.3 W
D. 250 W
Answer» D. 250 W
Discussion
3376.

In the circuit of figure the voltage across C at t = 0+ is

A. 0 V
B. 20 V
C. very large
D. 7.5 V
Answer» B. 20 V
Discussion
3377.

If A = 16 64 , (A)0.5 is

A. 4 64
B. 4 8
C. 4 128
D. 4 32
Answer» E.
Discussion
3378.

The frame of electric motor is connected to three plates having earthing resistance of 10 &amp;ohm;, 20 &amp;ohm; and 30 &amp;ohm; respectively. The materials of the three plates are copper, aluminium and iron respectively. The percentage of energy dissipated by 10 &amp;ohm; earthing plate

A. is more than 50% of total energy
B. is less than 50% of total energy
C. depends on the materials of the three plates
D. may be more or less than 50% of total energy
Answer» B. is less than 50% of total energy
Discussion
3379.

Assertion (A): When excited by a unit step voltage, an inductor behaves as open circuit at t = 0.Reason (R): Inductance has the property of inertia.

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
Discussion
3380.

Two coil have their axis perpendicular to each other. The coefficient of coupling k is

A. 1
B. 0.5
C. more than 0 but less than 1
D. 0
Answer» E.
Discussion
3381.

A bulb rated at 60 W, 120 V is used for 30 minutes. The charge associated with this operation is

A. 3600 C
B. 900 C
C. 7200 C
D. 600 C
Answer» C. 7200 C
Discussion
3382.

In a series RLC circuit, p-f is leading if XC &lt; XL.

A. True
B. False
Answer» C.
Discussion
3383.

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
Discussion
3384.

Three resistance of 15 &amp;ohm; each are connected in delta. The resistance of equivalent star will have a value of

A. 15 &ohm;
B. 5 &ohm;
C. 5/3 &ohm;
D. 45 &ohm;
Answer» C. 5/3 &ohm;
Discussion
3385.

The circuit in figure(1) is replaced by that in figure(2). It remains same R0 will be

A. zero
B. R
C. 2R
D. 4R
Answer» E.
Discussion
3386.

In a varistor the v-i graph is linear.

A. True
B. False
Answer» C.
Discussion
3387.

In the circuit of figure the current through 5 &amp;ohm; resistance at t = 0+ is

A. 4 A
B. 2.5 A
C. 3.1 A
D. 0 A
Answer» B. 2.5 A
Discussion
3388.

When cells having different emfs are connected in parallel, a circulating current flows.

A. True
B. False
Answer» B. False
Discussion
3389.

In a specimen of cast iron, a field strength of 400 AT/m cause a flux density of 0.6 T. In a specimen of silicon steel, the same value of H would cause B to be

A. 0.6 T
B. more than 0.6 T
C. less than 0.6 T
D. 0.6 T or less than 0.6 T
Answer» E.
Discussion
3390.

The circuit shown in figure, will act as an ideal current source with respect to terminals A and B, when frequency is

A. zero
B. 1 rad/s
C. 4 rad/s
D. 16 rad/s
Answer» D. 16 rad/s
Discussion
3391.

An RL admittance function can also be realized as

A. RC admittance function
B. RC impedance function
C. LC admittance function
D. LC impedance function
Answer» C. LC admittance function
Discussion
3392.

For a network having 1 &amp;ohm; resistor and 1 F capacitor in series Z(s) =

A. <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/112-542-1.png">
B. <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/112-542-2.png">
C. 1 +
D. <i>s</i>
E. <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/112-542-3.png">
Answer» B. <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/112-542-2.png">
Discussion
3393.

In given figure the switch was closed for a long time before opening at t = 0. The voltage Vx at t = 0+ is

A. 25 V
B. 50 V
C. -50 V
D. 0 V
Answer» D. 0 V
Discussion
3394.

The ac bridge shown in the figure is balanced if and Z4 is equal to

A. <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/143-996-3.png">
B. <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/143-996-4.png">
C. <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/143-996-5.png">
D. <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/143-996-6.png">
Answer» C. <img src="/_files/images/electronics-and-communication-engineering/networks-analysis-and-synthesis/143-996-5.png">
Discussion
3395.

A two branch parallel tuned circuit has a capacitance C in one of the two branches and resistance R in second branchs. As C is decreased the dynamic resistance

A. increases
B. decreases
C. remains constant
D. may increases or decreases
Answer» B. decreases
Discussion
3396.

Volt is equivalent to

A. joule/coulomb
B. joule/watt
C. joule/ampere
D. joule/volt
Answer» B. joule/watt
Discussion
3397.

A system function the resonant frequency in rad/sec and bandwidth in rad/sec is given by

A. 5, 10
B. 5, 4
C. 10, 4
D. 10, 10
Answer» D. 10, 10
Discussion
3398.

The reading of the voltmeter in figure will be __________ volt.

A. 100
B. 150
C. zero
D. 200
Answer» D. 200
Discussion
3399.

Find RL for maximum power transfer

A. 3 &ohm;
B. 1.125 &ohm;
C. 4.17 &ohm;
D. none
Answer» B. 1.125 &ohm;
Discussion
3400.

In an R-C circuit, the impedance is 40 &amp;ohm; at a frequency of 100 Hz. At 200 Hz the impedance should be

A. 40 &ohm;
B. 80 &ohm;
C. 20 &ohm;
D. more than 20 &ohm; but less than 40 &ohm;
Answer» E.
Discussion