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.

351.

For the circuit in the given figure,

A. <img src="/_files/images/electronics-and-communication-engineering/automatic-control-systems/21-167-1.png">
B. <img src="/_files/images/electronics-and-communication-engineering/automatic-control-systems/21-167-2.png">
C. <img src="/_files/images/electronics-and-communication-engineering/automatic-control-systems/21-167-3.png">
D. <img src="/_files/images/electronics-and-communication-engineering/automatic-control-systems/21-167-4.png">
Answer» D. <img src="/_files/images/electronics-and-communication-engineering/automatic-control-systems/21-167-4.png">
Discussion
352.

In Bode diagram (log magnitude plot) the factor in the transfer function gives a line having slope

A. -20 dB per octave
B. -10 dB per octave
C. -6 dB per octave
D. -2 dB per octave
Answer» D. -2 dB per octave
Discussion
353.

A negative feedback system has . The closed loop system is stable for

A. K > 20
B. 15 < K < 19
C. 8 K 14
D. K < 6
Answer» E.
Discussion
354.

Stepper motors find applications in

A. X-Y plotters
B. numerically controlled machining equipment
C. printers
D. all of the above
Answer» E.
Discussion
355.

For type 2 system, the magnitude and phase angle of the term (j )2 in the denominator, at = 0, are respectively

A. 0 and - 90
B. 0 and + 90
C. infinity and - 180
D. infinity and + 180
Answer» D. infinity and + 180
Discussion
356.

A lag compensator is essentially a

A. low pass filter
B. high pass filter
C. band pass filter
D. either (a) or (b)
Answer» B. high pass filter
Discussion
357.

In an integral controller

A. the output is proportional to input
B. the rate of change of output is proportional to input
C. the output is proportional to rate of change of input
D. none of the above
Answer» C. the output is proportional to rate of change of input
Discussion
358.

The input impedance of op-amp circuit of figure is

A. 120 k ohm
B. 110 k ohm
C. infinity
D. 10 k ohm
Answer» E.
Discussion
359.

The load impedance ZL of a CE amplifier has R and L in series. The phase difference between output and input will be

A. 180
B. 0
C. more than 90 but less than 180
D. more than 180 but less than 270
Answer» E.
Discussion
360.

Gain of the amplifier is 'A'. Then the I/P impedance and O/P impedance of the closed loop amplifier shown below would be

A. <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/330-480-2.png">
B. <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/330-480-3.png">
C. <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/330-480-4.png">
D. <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/330-480-5.png">
Answer» C. <img src="/_files/images/electronics-and-communication-engineering/analog-electronics/330-480-4.png">
Discussion
361.

In a BJT circuit a pnp transistor is replaced by npn transistor. To analyse the new circuit

A. all calculations done earlier have to be repeated
B. replace all calculated voltages by reverse values
C. replace all calculated currents by reverse values
D. replace all calculated voltages and currents by reverse values
Answer» E.
Discussion
362.

To protect the diodes in a rectifier and capacitor input filter circuit it is necessary to use

A. surge resistor
B. surge inductor
C. surge capacitor
D. both (a) and (b)
Answer» B. surge inductor
Discussion
363.

An RC coupled amplifier has an open loop gain of 200 and a lower cutoff frequency of 50 Hz. If negative feedback with = 0.1 is used, the lower cut off frequency will be

A. about 50 Hz
B. about 5 Hz
C. about 2.38 Hz
D. about 70.5 Hz
Answer» D. about 70.5 Hz
Discussion
364.

If an amplifier with gain of - 1000 and feedback factor = - 0.1 had a gain change of 20% due to temperature, the change in gain of the feedback amplifier would be

A. 10%
B. 5%
C. 0.2%
D. 0.01%
Answer» D. 0.01%
Discussion
365.

In a ballistic galvanometer, a charge of 100 C gives a first swing of 25 . The charge required to cause first swing of 50 is

A. 200 C
B. 400 C
C. 50 C
D. 25 C
Answer» C. 50 C
Discussion
366.

Two resistors R1 = 36 &amp;ohm; 5% and R2 = 75 &amp;ohm; 5% are connected in series. The total resistance is

A. 111 0 &ohm;
B. 111 2.778 &ohm;
C. 111 5.55 &ohm;
D. 111 7.23 &ohm;
Answer» D. 111 7.23 &ohm;
Discussion
367.

Which of the following statement is correct for two wattmeters method of power measurement in 3 phase circuit?

A. Power can be measured by this method only for star connected loads
B. When two wattmeters have equal readings power factor is 0.5.
C. When power factor is 1, one of the wattmeters readings is zero
D. When the two wattmeter read equal and opposite, p.f. is zero.
Answer» E.
Discussion
368.

Induction wattmeter can be used in

A. ac circuit only
B. dc circuit only
C. both ac and dc circuit
D. ac 3 phase only
Answer» B. dc circuit only
Discussion
369.

In a thermocouple temperature transducer, the output voltage is usually measured by

A. high resistance ammeter
B. high resistance voltmeter
C. high resistance milli-voltmeter
D. none of the above
Answer» D. none of the above
Discussion
370.

A moving coil instrument has a resistance of 0.6 &amp;ohm; and full scale deflection at 0.1 A. To convert it into an ammeter of 0-15 A range, the resistance of shunt should be

A. 0.6 &ohm;
B. 0.06 &ohm;
C. 0.1 &ohm;
D. 0.004 &ohm;
Answer» E.
Discussion
371.

A piezoelectric force transducer has a charge sensitivity of 20 pC/N. It is connected to a charge amplifier and overall gain of transducer and amplifier is 50 mV/N. The gain of amplifier is

A. 1 mV/pC
B. 1.5 mV/pC
C. 2.5 mV/pC
D. 4 mV/pC
Answer» D. 4 mV/pC
Discussion
372.

A moving iron instrument gives correct reading when used at

A. low frequencies
B. high frequencies
C. only one frequency
D. all frequencies upto a certain value
Answer» D. all frequencies upto a certain value
Discussion
373.

Whether a linear system is stable or unstable that it

A. is a property of the system only
B. depends on the input function only
C. both (a) and (b)
D. either (a) or (b)
Answer» B. depends on the input function only
Discussion
374.

For the system of the given figure the transfer function =

A. <img src="/_files/images/electronics-and-communication-engineering/automatic-control-systems/11-12-1.png">
B. <img src="/_files/images/electronics-and-communication-engineering/automatic-control-systems/11-12-2.png">
C. <img src="/_files/images/electronics-and-communication-engineering/automatic-control-systems/11-12-3.png">
D. <img src="/_files/images/electronics-and-communication-engineering/automatic-control-systems/11-12-4.png">
Answer» C. <img src="/_files/images/electronics-and-communication-engineering/automatic-control-systems/11-12-3.png">
Discussion
375.

To prevent a DC return between source and load, it is necessary to use

A. resistor between source and load
B. inductor between source and load
C. capacitor between source and load
D. either (a) or (b)
Answer» D. either (a) or (b)
Discussion
376.

For a base current of 10 A, what is the value of collector current in common emitter if dc = 100

A. 10 A
B. 100 A
C. 1 mA
D. 10 mA
Answer» D. 10 mA
Discussion
377.

Which of the following oscillators is suitable for frequencies in the range of mega hertz?

A. RC phase shift
B. Wien bridge
C. Hartley
D. Both (a) and (c)
Answer» D. Both (a) and (c)
Discussion
378.

If the input to the ideal comparator shown in the figure is a sinusoidal signal of 8 V (peak to peak) without any DC component, then the output of the comparator has a duty cycle of

A. 1/2
B. 1/3
C. 1/6
D. 1/12
Answer» C. 1/6
Discussion
379.

In a CRO which of the following is not a part of electron gun

A. cathode
B. grid
C. accelerating anode
D. X - Y plates
Answer» E.
Discussion
380.

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
Discussion
381.

An RLC series circuit is underdamped. To make it overdamped, the value of R

A. has to be increased
B. has to be decreased
C. has to be increased to infinity
D. has to be reduced to zero
Answer» B. has to be decreased
Discussion
382.

Henry is equivalent to

A. Volts/Ampere
B. Weber/Volt
C. Weber/Ampere
D. Weber/Ampere
E. <sup>2</sup>
Answer» D. Weber/Ampere
Discussion
383.

In a parallel resonant circuit, the circuit current at resonance is maximum.

A. True
B. False
Answer» C.
Discussion
384.

If a piece of wood is placed in a magnetic field

A. the magnetic field will not be affected
B. the magnetic lines of force will bend towards the piece
C. the magnetic lines of force will bend away from the piece
D. the flux may increase or decrease
Answer» B. the magnetic lines of force will bend towards the piece
Discussion
385.

The number of valence electrons in donor impurity are

A. 5
B. 4
C. 3
D. 1
Answer» B. 4
Discussion
386.

The apparent capacitance at a high angular frequency of an air cored capacitor having capacitance C and inductance L is given by

A. <img src="/_files/images/electronics-and-communication-engineering/materials-and-components/238-1.png">
B. <img src="/_files/images/electronics-and-communication-engineering/materials-and-components/238-2.png">
C. <img src="/_files/images/electronics-and-communication-engineering/materials-and-components/238-3.png">
D. <img src="/_files/images/electronics-and-communication-engineering/materials-and-components/238-4.png">
Answer» C. <img src="/_files/images/electronics-and-communication-engineering/materials-and-components/238-3.png">
Discussion
387.

In a true valence crystal, the bonding between the atoms is accomplished by the sharing of valence electrons.

A. True
B. False
Answer» B. False
Discussion
388.

The number of valence electrons in pentavalent impurity is

A. 5
B. 4
C. 3
D. 1
Answer» B. 4
Discussion
389.

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

A. one-fourth
B. half
C. twice
D. four times
Answer» E.
Discussion
390.

Which of the following are donor impurities? GoldPhosphorusBoronAntimonyArsenicInduim Select the correct answer using the following codes

A. 1, 2, 3
B. 1, 2, 4, 6
C. 3, 4, 5, 6
D. 2, 4, 5
Answer» E.
Discussion
391.

Assertion (A): Silicon is less sensitive to changes in temperature than germanium.Reason (R): Cut in voltage in silicon is less than that in germanium.

A. Both A and R are true and R is correct explanation of A
B. Both A and R are true but R is not correct explanation of A
C. A is true but R is false
D. A is false but R is true
Answer» D. A is false but R is true
Discussion
392.

If n denotes principal quantum number, the angular quantum number l = 0, 1... (n - 1).

A. True
B. False
Answer» B. False
Discussion
393.

Which element exhibits the property of inertia?

A. Resistance
B. Capacitance
C. Inductance
D. Both resistance and inductance
Answer» D. Both resistance and inductance
Discussion
394.

For a permanent magnetic material

A. the residual induction and coercive field should be large
B. the residual induction and coercive field should be small
C. area of hysteresis loop should be small
D. initial relative permeability should be high
Answer» B. the residual induction and coercive field should be small
Discussion
395.

In a coaxial cable, braided copper is used for

A. conductor
B. shield
C. dielectric
D. jacket
Answer» C. dielectric
Discussion
396.

A parallel plate capacitor has its length, width and separation doubled. It fringing effects are neglected, to keep the capacitance same, the dielectric constant must be

A. halved
B. kept the same
C. doubled
D. made 4 times
Answer» B. kept the same
Discussion
397.

Assertion (A): In imperfect capacitors, the current does not lead the applied ac voltage by 90 .Reason (R): When subjected to ac fields, the dielectric constant can be expressed as 'r - j "r.

A. Both A and R are true and R is correct explanation of A
B. Both A and R are true but R is not 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 but R is not correct explanation of A
Discussion
398.

In atomic physics, a state with l = 0 is called p state.

A. True
B. False
Answer» C.
Discussion
399.

Assertion (A): From the slope of the line in Figure, we can find permanent dipole moment of the molecules.Reason (R): Total polarization of a polyatomic gas is given by P = N(ae + ai + 2p / 3kT)E.

A. Both A and R are true and R is correct explanation of A
B. Both A and R are true but R is not 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 but R is not correct explanation of A
Discussion
400.

Assertion (A): If E is available energy state eV and EF is Fermi level, then probability of energy state E being occupied = 0.5.Reason (R): .

A. Both A and R are true and R is correct explanation of A
B. Both A and R are true but R is not 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
Discussion