Explore topic-wise InterviewSolutions in .

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

94201.

If there are 3 10V sources connected in parallel then on source transformation__________(a) The effect of all the sources is considered(b) The effect of only one source is considered(c) The effect of none of the sources is considered(d) The effect of only 2 sources is considered.

Answer» Right choice is (b) The effect of only one source is considered

For explanation: When voltages are connected in parallel, the effect of only one source is considered because the effect of the voltage remains the same when connected in parallel.
94202.

What is the equivalent capacitance?(a) 1.5F(b) 0.667F(c) 2.45F(d) 2.75F

Answer» Correct choice is (b) 0.667F

The best explanation: When capacitors are connected in series,

1/Ctotal = 1/C1+1/C2 = 1/2+1 = 3/2

Ctotal = 2/3 = 0.667F.
94203.

What will be the optimum pouring time for cast iron whose mass is 100 kg and a thickness of 25 mm? Fluidity of iron is 32 inches?(a) 24.98(b) 18.2(c) 31.32(d) 14.8

Answer» The correct option is (a) 24.98

For explanation I would say: Pouring time(t) = K[ 1.41 + T/14.59]√W sec.

     where K = Fluidity of iron in inches/40

Pouring time(t) = 32/40[ 1.41 + 25/14.59]√100 = 24.988 sec.
94204.

At resonance, the circuit appears __________(a) Inductive(b) Capacitive(c) Either inductive or capacitive(d) Resistive

Answer» The correct choice is (d) Resistive

For explanation: At resonance, the circuit appears resistive because the capacitive and inductive energies are equal to each other.
94205.

The liquid metal that runs through the channels without friction in the mould obeys which of the following theorem?(a) Bernoulli’s theorem(b) Clausius theorem(c) Helmholtz’s theorem(d) Carnot’s theorem

Answer» Right answer is (a) Bernoulli’s theorem

To explain: As the metal enters the pouring basin, it has the highest potential energy with no kinetic or pressure energies. But as the metal moves through the gating system, potential energy converts into kinetic energy. Thus it obeys the Bernoulli’s theorem.
94206.

“Total electric flux through any closed surface is equal to the charge enclosed by that surface divided by permittivity”. This is the statement for?(a) Gauss law(b) Lenz law(c) Coloumb’s law(d) Faraday’s law

Answer» The correct choice is (a) Gauss law

To explain: Total electric flux through any closed surface is equal to the charge enclosed by that surface divided by permittivity is the statement for Gauss law because among the four laws, Gauss law deals with electric flux.
94207.

What happens to the capacitance of a multi plate capacitor when the distance of separation between the plate increases?(a) Increases(b) Decreases(c) Remains constant(d) Becomes zero

Answer» Correct answer is (b) Decreases

The explanation is: When the distance of separation between the plates increases, the capacitance decreases since it is related by the formula C=Actual permittivity*(n-1)*A/d. Here, we can see that the capacitance is inversely proportional to the distance of separation.
94208.

Calculate the voltage across the 2F capacitor.(a) 33.33V(b) 66.67V(c) 56.56V(d) 23.43V

Answer» Correct option is (a) 33.33V

Explanation: When capacitors are connected in series,

1/Ctotal=1/C1+1/C2 = 1/2+1 = 3/2

Q = CV = (2/3)*100 = 66.67C.

V across the 2F capacitor = 66.67/2 = 33.33V.
94209.

At resonance, the capacitive energy is ___________ inductive energy.(a) Greater than(b) Less than(c) Equal to(d) Depends on the circuit

Answer» Correct option is (c) Equal to

Easiest explanation: At resonance, energy stored in the capacitor is equal to energy stored in the inductor because capacitive reactance and inductive reactance are equal at resonance.                So, at resonance, capacitive energy is equal to inductive energy.
94210.

What is the frequency in resonance condition?(a) Minimum(b) Maximum(c) Cannot be determined(d) Zero

Answer» The correct option is (b) Maximum

The best I can explain: At resonance condition, the frequency is maximum since the inductive reactance is equal to the capacitive reactance. XL=XC.
94211.

If a parallel plate capacitor of plate area 2m^2 and plate separation 1m store the charge of 1.77*10^-11 C. What is the voltage across the capacitor?(a) 1V(b) 2V(c) 3V(d) 4V

Answer» Correct answer is (a) 1V

Explanation: C=€0A/d

On substituting values of d, A, we get C=2€0.

Q=CV

V=1 V.
94212.

Choke involve use of _____________(a) Resistor(b) Capacitor(c) Inductor(d) Transistor

Answer» Correct option is (c) Inductor

The best explanation: Choke is a type of coil so it involves use of inductor. Capacitors cannot be used in choke coil.
94213.

What is the resonance frequency of ac circuit?(a) 1/√LC(b) √(L/C)(c) √LC(d) LC

Answer» Correct option is (a) 1/√LC

Easiest explanation: At resonance, XL=XC

ωL=1/ωC

ω=1/√LC.
94214.

Find the value of the source voltage from the following circuit.(a) 49.2V(b) 34.6V(c) 65.2V(d) 25.6V

Answer» The correct choice is (a) 49.2V

For explanation I would say: I3 =(3+j0)A

V2 =I3R=(3+j0)(8+j0)=(24+j0)V

I2=V2/Xc=(0 + j1.5) A

I1 =I2 +I3 =(0+j1.5)+(3+j0)=(3+j1.5)A

I1=(3^2+1.5^2)^1/2= 3.35A.

V1 =I1(R+jXL) =(15+j30)V

E=V1 +V2 =(39+j30)V

E=(39^2+30^2)^1/2= 49.2V.
94215.

The insulant between the two plates of a capacitor is called _______(a) Conductor(b) Semi-conductor(c) Dielectric(d) Superconductor

Answer» The correct option is (c) Dielectric

The best I can explain: The material between the two plates of a capacitor is an insulator, more specifically known as a dielectric.
94216.

In an RLC circuit, which of the following is always used as a vector reference?(a) Voltage(b) Resistance(c) Impedance(d) Current

Answer» The correct option is (a) Voltage

To explain I would say: In an RLC circuit, the voltage is always used as a reference and according to the phase of the voltage, the phase of the other parameters is decided.
94217.

What is not a frequency for ac current?(a) 50 Hz(b) 55 Hz(c) 0Hz(d) 60 Hz

Answer» The correct answer is (c) 0Hz

Easiest explanation: DC current is a type of constant current so it has frequency of zero hertz.                                                                                                          So, AC current can have rest other frequencies other than zero.
94218.

A capacitor using chemical reactions to store charge is _______(a) Paper capacitor(b) Ceramic capacitor(c) Polyester capacitor(d) Electrolyte capacitor

Answer» Correct choice is (d) Electrolyte capacitor

To explain: Electrolyte capacitors use chemical processes like pyrolysis to store charge between its plates.
94219.

What is sinϕ from impedance triangle?(a) XL/R(b) XL/Z(c) R/Z(d) Z/R

Answer» Correct answer is (b) XL/Z

The explanation: In Impedance triangle, Base is R, Hypotenuse is Z, Height is XL.

So, sinϕ = XL/Z.
94220.

In an RLC circuit, the power factor is always ____________(a) Positive(b) Negative(c) Depends on the circuit(d) Zero

Answer» Correct option is (c) Depends on the circuit

The explanation: In an RLC series circuit, the power factor depends on the number of resistors and inductors in the circuit, hence it depends on the circuit.
94221.

Which, among the following qualities, is not affected by the magnetic field?(a) Moving charge(b) Change in magnetic flux(c) Current flowing in a conductor(d) Stationary charge

Answer» The correct answer is (d) Stationary charge

To explain: A stationary charge is not affected by a magnetic field because stationary charges do not have any velocity. Magnetic field cannot occur in a particle having zero velocity.
94222.

A resistance of 7 ohm is connected in series with an inductance of 31.8mH. The circuit is connected to a 100V 50Hz sinusoidal supply. Calculate the voltage across the inductor.(a) 52V(b) 82V(c) 65V(d) 76V

Answer» Correct option is (b) 82V

The best explanation: XL=2*π*f*L = 10 ohm. Z^2=(R^2+XL^2)

Therefore, the total impedance Z = 12.2ohm.

V=IZ, therefore I=V/Z=100/12.2 = 8.2A.                                                                                                             Voltage across inductor = 8.2*10 = 82V.
94223.

In superposition theorem, when we consider the effect of one current source, all the other current sources are ____________(a) Shorted(b) Opened(c) Removed(d) Undisturbed

Answer» Right answer is (b) Opened

Explanation: In superposition theorem, whether we consider the effect of a voltage or current source, current sources are always opened and voltage sources are always shorted.
94224.

Superposition theorem does not work for ________(a) Current(b) Voltage(c) Power(d) Works for all: current, voltage and power

Answer» Correct answer is (c) Power

The explanation is: Power across an element is not equal to the power across it due to all the other sources in the system. The power in an element is the product of the total voltage and the total current in that element.
94225.

Which, among the following, is the correct expression for φ.(a) φ=tan^-1 (XL/R)(b) φ=tan^-1 (R/XL)(c) φ=tan^-1 (XL*R)(d) φ=cos^-1 (XL/R)

Answer» The correct option is (a) φ=tan^-1 (XL/R)

The best I can explain: From the impedance triangle, we get tanφ= XL/R.

Hence φ=tan^-1 (XL/R).
94226.

The quadrature component is also known as?(a) Active component(b) Reactive component(c) Either active or reactive component(d) Neither active nor reactive component

Answer» Correct answer is (b) Reactive component

To explain: The quadrature component is also known as the reactive component because the reactive component forms a quadrature with the voltage.
94227.

What is the power factor of a series RLC circuit under resonance condition?(a) 0(b) 1(c) Infinity(d) 100

Answer» Right choice is (b) 1

For explanation: The power factor for a series RLC circuit in resonance condition is always unity because the current is in phase with the voltage under resonance condition.

Φ=0^0 => cos ϕ = 1  i.e.  power factor = 1.
94228.

What is the real part of the impedance of RLC circuit?(a) Resistance(b) Conductance(c) Admittance(d) Reactance

Answer» Right option is (a) Resistance

For explanation I would say: The combination of resistance and reactance is known as impedance.                                                                              Z=R+jX    where Z is impedance, R is resistance and X is reactance.                                                               R is real part of Z.
94229.

Force in a conductor is__________ to the product of the charges.(a) Directly proportional(b) Inversely proportional(c) Not related(d) Cannot be determined

Answer» The correct choice is (a) Directly proportional

Best explanation: The force in a current carrying conductor is directly proportional to the product of the two charges and inversely proportional to the square of the distance between them.
94230.

Which of the following is not a line segment?(a) Bamboo(b) Ruler(c) Laser beam(d) Pencil

Answer» Correct option is (c) Laser beam

To explain: A line segment is a part of a line that is bounded by two distinct end points, and contains every point on the line between its endpoints. A ray is a line with one end goes forever in the other direction. Here option Laser beam is ray and others are line segment.
94231.

What is imaginary part of the impedance of RLC circuit?(a) Resistance(b) Conductance(c) Admittance(d) Reactance

Answer» Right answer is (d) Reactance

Explanation: The combination of resistance and reactance is known as impedance.                                                                              Z=R+jX    where Z is impedance, R is resistance and X is reactance.                                                               X is imaginary part of Z.
94232.

What is the consequence of motor effect?(a) Current(b) Voltage(c) Electromagnetic induction(d) EMF

Answer» Right choice is (c) Electromagnetic induction

The best I can explain: Motor effect is when a current carrying conductor in a magnetic field experiences a force, hence its consequence is electromagnetic induction.
94233.

If X is a point on AB and A – X – B (X is between A and B), then AB =?(a) AX + XB(b) AB – XB(c) AB – XA(d) AX – XB

Answer» The correct answer is (a) AX + XB

For explanation I would say: The part of a line that connects two points. It has definite end points. Adding the word “segment” is important, because a line normally extends in both directions without end.  The figure shows a line segment AB with point C. Point C can divide the line segment in any ratio.
94234.

When is tanφ negative?(a) When inductive reactance is less than capacitive reactance(b) When inductive reactance is greater than capacitive reactance(c) When inductive reactance is equal to capacitive reactance(d) When inductive reactance is zero

Answer» The correct option is (a) When inductive reactance is less than capacitive reactance

To explain I would say: tanφ is negative when inductive reactance is less than capacitive reactance because current will lead the voltage.
94235.

Magnetic field exists along which of the following?(a) Moving charges(b) Stationary charges(c) Copper(d) Iron

Answer» Right choice is (a) Moving charges

To explain: Moving charges have a magnetic field associated with them because they have magnetic flux lines associated with it.
94236.

What type of line is B in the following figure?(a) Inner line(b) Outline(c) Outer line(d) Boundary line

Answer» Right choice is (b) Outline

The best I can explain: Outlines represents a general sketch indicating only the main features, aspect of something under discussion. These are continuous thick, wide lines used to represent visible edges and surface boundaries of objects.  Also known as principal lines.
94237.

Which, among the following, have negative susceptibility?(a) Diamagnetic(b) Paramagnetic(c) Ferromagnetic(d) Not a magnetic substance

Answer» Correct option is (a) Diamagnetic

To explain I would say: Magnetic susceptibility is the degree of magnetisation of a material in response to the external magnetic field. Diamagnetic substances repel the magnetic field and hence have negative susceptibility.
94238.

The B/H ratio is not constant for ________(a) Diamagnetic materials(b) Ferromagnetic materials(c) Paramagnetic materials(d) Non-magnetic materials

Answer» The correct choice is (b) Ferromagnetic materials

The best explanation: As the magnetizing field increases, the relative permeability increases, reaches a maximum, and then decreases. Due to varying permeability, B/H ratio is not constant for ferromagnetic materials.
94239.

You are asked to construct a massive dam, the type of cement you will use, is?(a) Ordinary Portland cement(b) Blast furnace slag cement(c) White cement(d) Low heat cement

Answer» The correct answer is (d) Low heat cement

Easy explanation: Dam construction will involve mass concreting where heat of hydration is the major concern which if not monitored will cause crack in the bulk of the dam which is undesirable, hence low heat cement is preferable in this type of concreting.
94240.

What is the principle of the transformer?(a) Gauss law(b) Coulomb’s law(c) Electromagnetic induction(d) Ampere’s law

Answer» Right option is (c) Electromagnetic induction

To elaborate: In transformer, flux in secondary coil change due to current in the primary coil and hence current get induced in secondary coil.
94241.

If you are given only a compass and a ruler which angle is not possible to construct?(a) 37.5(b) 33.75(c) 40(d) 120

Answer» The correct choice is (c) 40

Easy explanation: It is not possible to construct an angle that is not a multiple of 15. Angle 40 is not a multiple of 15 while 120 is multiple of 15. Angle 37.5 is formed by angular bisector of angle 75 which is again a multiple of 15. Angle 33.75 is formed by bisecting angle 135 two times, is also a multiple of 15.
94242.

Calculate the magnetic flux density if the magnetic field strength is 3A/m.(a) 4*pi*10^-7T(b) 8*pi*10^-7T(c) 10*pi*10^-7T(d) 12*pi*10^-7T

Answer» Correct answer is (d) 12*pi*10^-7T

For explanation: We know that:

µ0=B/H

Substituting the value of H from the question, we get B = 12*pi*10^-7T.
94243.

Calculate the magnetic field strength if the magnetic flux density is 4*piT.(a) 10^-7/16*pi^2A/m(b) 10^-7A/m(c) 10^7A/m(d) 10^-7A

Answer» Correct choice is (c) 10^7A/m

The explanation: We know that:

µ0=B/H

Substituting the value of B from the question, we get H = 10^7A/m.
94244.

What must you be given to construct an equilateral triangle by compass?(a) One side(b) One angle(c) Two side(d) One angle and one side

Answer» The correct answer is (a) One side

Easiest explanation: An equilateral triangle is one which has all three sides of the same length. For the figure given below, with centres P and Q and radius equal to PQ, draw arcs intersecting each other at R. After this draw lines joining R with P and Q. The triangle obtained is the equilateral triangle.
94245.

What is a permeable substance?(a) Any good conductor(b) Any bad conductor(c) Any strong magnet(d) Any substance through which the magnetic lines of force can pass easily

Answer» Right option is (d) Any substance through which the magnetic lines of force can pass easily

Explanation: A permeable substance is one through which the magnetic lines of force can pass easily.
94246.

Calculate the magnetic flux density if the magnetic field strength is 2A/m.(a) 4*pi*10^-7T(b) 8*pi*10^-7T(c) 10*pi*10^-7T(d) 12*pi*10^-7T

Answer» Correct choice is (b) 8*pi*10^-7T

Easy explanation: We know that:

µ0=B/H

Substituting the value of H from the question, we get B = 8*pi*10^-7T.
94247.

Which of the property given below is false regarding a square?(a) A square is a particular case of a rectangle and a rhombus simultaneously(b) A square is a parallelogram with right angles and equal sides(c) The diagonals of a square cut at 90 degree(d) A square is a particular case of a rectangle only

Answer» The correct answer is (d) A square is a particular case of a rectangle only

The best I can explain: Square is a combination of the properties of a rectangle and a rhombus, i.e. with four congruent sides similar to rhombus and with four right angles same as of rectangle. This can be understood from the figure below.
94248.

The angle bisector bisects the angle exactly __________(a) Perpendicular(b) 60 degree(c) Half(d) Any ratio

Answer» Correct answer is (c) Half

To explain I would say: The bisector of an angle is a ray whose end point is the vertex of the angle and which divides the angle into two equal angles. For the figrure given below  BD line is the angular bisector dividing angle ABC in two equal parts.
94249.

Which of the following is not true regarding concentric and eccentric circles?(a) Concentric circles have a common centre point(b) Eccentric circles have no common centre point(c) Concentric circles have no common centre point(d) Two or more circles with a common centre point are called concentric

Answer» The correct option is (d) Two or more circles with a common centre point are called concentric

Easiest explanation: When a circle is fully contained within another circle, they can be either eccentric or concentric. If they share the same centre, they are called concentric (please refer figure a) or else, they are said to be eccentric (please refer figure b).
94250.

According to _________________ induced emf is equal to rate of change of magnetic flux.(a) Newton’s law(b) Lenz law(c) Faraday’s law(d) Coulomb’s law

Answer» Right answer is (c) Faraday’s law

For explanation: According to Faraday law of electromagnetic induction, induced emf is equal to rate of change of magnetic flux.