# 600+ Electromagnetics Solved MCQs

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46.5k
1.

A. true
B. false
2.

A. tangent
B. chord
C. slope
D. arc
3.

## Divergence of gradient of a vector function is equivalent to

A. laplacian operation
B. curl operation
D. null vector
4.

## Curl of gradient of a vector is

A. unity
B. zero
C. null vector
D. depends on the constants of the vector
5.

## Find the gradient of the function given by, x2 + y2 + z2 at (1,1,1)

A. i + j + k
B. 2i + 2j + 2k
C. 2xi + 2yj + 2zk
D. 4xi + 2yj + 4zk
Answer» B. 2i + 2j + 2k
6.

## The gradient can be replaced by which of the following?

A. maxwell equation
B. volume integral
C. differential equation
D. surface integral
7.

## . Find the gradient of the function sin x + cos y.

A. cos x i – sin y j
B. cos x i + sin y j
C. sin x i – cos y j
D. sin x i + cos y j
Answer» A. cos x i – sin y j
8.

A. true
B. false
9.

A. true
B. false
10.

A. 0
B. 1
C. 2
D. 3
11.

A. -1
B. 0
C. 1
D. 3
12.

## Find the divergence of the vector F= xe-x i + y j – xz k

A. (1 – x)(1 + e-x)
B. (x – 1)(1 + e-x)
C. (1 – x)(1 – e)
D. (x – 1)(1 – e)
Answer» A. (1 – x)(1 + e-x)
13.

## Find whether the vector is solenoidal, E = yz i + xz j + xy k

A. yes, solenoidal
B. no, non-solenoidal
C. solenoidal with negative divergence
D. variable divergence
14.

A. xyz + 2x
B. 2xyz + x
C. xyz + 2z
D. 2xyz + z
15.

## Identify the nature of the field, if the divergence is zero and curl is also zero.

A. solenoidal, irrotational
B. divergent, rotational
C. solenoidal, irrotational
D. divergent, rotational
16.

A. true
B. false
17.

18.

## Which of the following theorem use the curl operation?

A. green’s theorem
B. gauss divergence theorem
C. stoke’s theorem
D. maxwell equation
19.

## The curl of a curl of a vector gives a

A. scalar
B. vector
C. zero value
D. non zero value
20.

A. yes
B. no
21.

## Find the curl of A = (y cos ax)i + (y + ex)k

A. 2i – ex j – cos ax k
B. i – ex j – cos ax k
C. 2i – ex j + cos ax k
D. i – ex j + cos ax k
Answer» B. i – ex j – cos ax k
22.

## Find the curl of the vector A = yz i + 4xy j + y k

A. xi + j + (4y – z)k
B. xi + yj + (z – 4y)k
C. i + j + (4y – z)k
D. i + yj + (4y – z)k
Answer» D. i + yj + (4y – z)k
23.

## Curl cannot be employed in which one of the following?

A. directional coupler
B. magic tee
C. isolator and terminator
D. waveguides
24.

## Which of the following Maxwell equations use curl operation?

A. maxwell 1st and 2nd equation
B. maxwell 3rd and 4th equation
C. all the four equations
D. none of the equations
Answer» A. maxwell 1st and 2nd equation
25.

A. true
B. false
26.

A. 47.905
B. 57.905
C. 67.905
D. 77.905
27.

A. -8.014
B. -8.114
C. -8.214
D. -8.314
28.

A. solenoidal
B. rotational
C. irrotational
D. conservative
29.

A. 1
B. 0
C. -1
D.
30.

A. force
B. area
C. volume
D. length
31.

A. 0.2
B. 0.4
C. 0.6
D. 0.8
32.

A. true
B. false
33.

A. surface
B. area
C. volume
D. density
34.

A. true
B. false
35.

A. 600
B. 599.8
C. 588.9
D. 577.8
36.

## The ultimate result of the divergence theorem evaluates which one of the following?

A. field intensity
B. field density
C. potential
D. charge and flux
37.

## The divergence theorem converts

A. line to surface integral
B. surface to volume integral
C. volume to line integral
D. surface to line integral
Answer» B. surface to volume integral
38.

A. true
B. false
39.

A. true
B. false
40.

## Using volume integral, which quantity can be calculated?

A. area of cube
B. area of cuboid
C. volume of cube
D. distance of vector
41.

B. curl
C. divergence
D. laplacian
42.

## The Gauss divergence theorem converts

A. line to surface integral
B. line to volume integral
C. surface to line integral
D. surface to volume integral
Answer» D. surface to volume integral
43.

A. 1
B. 0
C. -1
D. 2
44.

A. true
B. false
45.

## Coulomb is the unit of which quantity?

A. field strength
B. charge
C. permittivity
D. force
46.

## Coulomb law is employed in

A. electrostatics
B. magnetostatics
C. electromagnetics
D. maxwell theory
47.

A. 18 x 106
B. -18 x 106
C. 18 x 10-6
D. -18 x 10-6
48.

## Two charges 1C and -4C exists in air. What is the direction of force?

A. away from 1c
B. away from -4c
C. from 1c to -4c
D. from -4c to 1c
Answer» C. from 1c to -4c
49.

## The Coulomb law is an implication of which law?

A. ampere law
B. gauss law
C. biot savart law
D. lenz law
50.

## For a charge Q1, the effect of charge Q2 on Q1 will be,

A. f1 = f2
B. f1 = -f2
C. f1 = f2 = 0
D. f1 and f2 are not equal
51.

## The electric field intensity is defined as

A. force per unit charge
B. force on a test charge
C. force per unit charge on a test charge
D. product of force and charge
Answer» C. force per unit charge on a test charge
52.

A. 0
B. 1
C. 2
D. 3
53.

A. zero
B. unity
C. σ/ε
D. σ/2ε
54.

A. unity
B. +∞
C. zero
D. -∞
55.

## The lines of force are said to be

A. real
B. imaginary
C. drawn to trace the direction
D. not significant
Answer» C. drawn to trace the direction
56.

## Electric flux density in electric field is referred to as

A. number of flux lines
B. ratio of flux lines crossing a surface and the surface area
C. direction of flux at a point
D. flux lines per unit area
Answer» B. ratio of flux lines crossing a surface and the surface area
57.

## The electric flux density is the

A. product of permittivity and electric field intensity
B. product of number of flux lines and permittivity
C. product of permeability and electric field intensity
D. product of number of flux lines and permeability
Answer» A. product of permittivity and electric field intensity
58.

## Which of the following correctly states Gauss law?

A. electric flux is equal to charge
B. electric flux per unit volume is equal to charge
C. electric field is equal to charge density
D. electric flux per unit volume is equal to volume charge density
Answer» D. electric flux per unit volume is equal to volume charge density
59.

## The Gaussian surface is

A. real boundary
B. imaginary surface
C. tangential
D. normal
60.

A. 12
B. 14
C. 16
D. 18
61.

A. 5.774
B. 6.774
C. 7.774
D. 8.774
62.

## The potential difference in an open circuit is

A. zero
B. unity
C. infinity
D. circuit does not exist open
63.

A. positive
B. negative
C. zero
D. infinity
64.

A. 2.386
B. 3.386
C. 4.386
D. 5.386
65.

## The voltage at any point in an ac circuit will be

A. peak voltage
B. rms voltage
C. average voltage
D. source voltage
66.

A. gauss law
B. stoke’s law
C. ampere law
D. lenz law
67.

A. sphere
B. cylinder
C. cube
D. cuboid
68.

A. cube
B. cylinder
C. sphere
D. cuboid
69.

A. 11
B. 33
C. 55
D. 77
70.

A. 32.86
B. 43.86
C. 54.68
D. 65.68
71.

## Gauss law cannot be used to find which of the following quantity?

A. electric field intensity
B. electric flux density
C. charge
D. permittivity
72.

A. div(e) = 0
B. div(b) = 0
C. div(h) = 0
D. div(d) = 0
73.

## Gauss law can be used to compute which of the following?

A. permittivity
B. permeability
D. electric potential
74.

## Gauss law can be evaluated in which coordinate system?

A. cartesian
B. cylinder
C. spherical
D. depends on the gaussian surface
Answer» D. depends on the gaussian surface
75.

## Gauss law cannot be expressed in which of the following forms?

A. differential
B. integral
C. point
D. stokes theorem
76.

A. ampere law
C. coulomb’s law
D. ohm’s law
77.

## The electric flux density and electric field intensity have which of the following relation?

A. linear
B. nonlinear
C. inversely linear
D. inversely nonlinear
78.

A. 96
B. 66
C. 30
D. -66
79.

A. 20
B. 10
C. 30
D. 60
80.

A. 96
B. 24
C. 36
D. 48
81.

## The distance vector is obtained in

A. cartesian coordinate system
B. spherical coordinate system
C. circular coordinate system
D. space coordinate system
82.

A. 0
B. 3
C. 2
D. 1
83.

A. –j – k
B. –i – j
C. –i – k
D. –i – j – k
84.

## The unit vector to the points p1(0,1,0), p2(1,0,1), p3(0,0,1) is

A. (-j – k)/1.414
B. (-i – k)/1.414
C. (-i – j)/1.414
D. (-i – j – k)/1.414
85.

## The polar form of Cartesian coordinates is

A. circular coordinates
B. spherical coordinates
C. cartesian coordinates
D. space coordinates
86.

## The work-electric field relation is given by

A. volume integral
B. surface integral
C. line integral
D. relation impossible
87.

## The distance vector can be used to compute which of the following?

A. dot product
B. cross product
C. unit normal vector
D. area
88.

A. true
B. false
89.

A. 6
B. 6.25
C. 6.5
D. 6.75
90.

## The del operator is called as

B. curl
C. divergence
D. vector differential operator
91.

B. divergence
C. curl
D. del operator
92.

C. curl(div v)
D. div(curl v)
93.

A. true
B. false
94.

A. true
B. false
95.

## Identify the correct vector identity.

A. i . i = j . j = k . k = 0
B. i x j = j x k = k x i = 1
C. div (u x v) = v . curl(u) – u . curl(v)
D. i . j = j . k = k . i = 1
Answer» C. div (u x v) = v . curl(u) – u . curl(v)
96.

## A vector is said to be solenoidal when its

A. divergence is zero
B. divergence is unity
C. curl is zero
D. curl is unity
97.

A. divergent
B. curl free
C. solenoidal
D. rotational
98.

## A field has zero divergence and it has curls. The field is said to be

A. divergent, rotational
B. solenoidal, rotational
C. solenoidal, irrotational
D. divergent, irrotational
99.

## When a vector is irrotational, which condition holds good?

A. stoke’s theorem gives non-zero value
B. stoke’s theorem gives zero value
C. divergence theorem is invalid
D. divergence theorem is valid
Answer» B. stoke’s theorem gives zero value
100.

## The Cartesian system is also called as

A. circular coordinate system
B. rectangular coordinate system
C. spherical coordinate system
D. space coordinate system