Bohol Island State University Main Campus
College of Engineering Architecture and Industrial Design
EE02
Electromagnetics
Activity 1.1
Introduction to Electromagnetics
An overview of the student's knowledge of
the course. Based on your research or your
confident
understanding,
answer
the
following
questions
below.
Write
the
question and your answer on a short size
bond paper, handwritten, and submit it in
[Last name, First name Year & Section –
A1.1].pdf format (e.g., Perocho, Jhon Rey
BSEE 2A – A1.1.pdf)
1. When two vectors are perpendicular,
their
a) Dot product is zero
b) Cross product is zero
c) Both are zero
d) Both are not necessarily zero
2. The cross product of the vectors 3i + 4j
– 5k and –i + j – 2k is,
a) 3i – 11j + 7k
b) -3i + 11j + 7k
c) -3i – 11j – 7k
d) -3i + 11j – 7k
8. The dot product of two vectors is a
scalar. The cross product of two vectors is
a vector. State True/False.
a) True
b) False
9. Which of the Pythagorean Theorem is
valid in Electromagnetics?
a) |dot product| + |dot product| = 1
b) |cross product| – |cross product| = 1
c) |dot product|2 + |cross product|2 = 1
d) |dot product| + |cross product| = 0
10. Which
a) A . (B
b) A . (B
c) A x (B
d) A x (B
of the
. C) =
x C) =
. C) =
x C) =
following is not true?
scalar value
scalar value
scalar value
vector value
11. The distance vector is obtained in
a) Cartesian coordinate system
b) Spherical coordinate system
c) Circular coordinate system
d) Space coordinate system
3. Which of the following are not vector
functions in Electromagnetics?
a) Gradient
b) Divergence
c) Curl
d) There is no non- vector functions in
Electromagnetics
12. The divergence of distance vector is
a) 0
b) 3
c) 2
d) 1
4. The work done of vectors force F and
distance d, separated by angle θ can be
calculated using,
a) Cross product
b) Dot product
c) Addition of two vectors
d) Cannot be calculated
13. Find a vector normal to a plane
consisting of points p1(0,1,0), p2(1,0,1)
and p3(0,0,1)
a) –j – k
b) –i – j
c) –i – k
d) –i – j – k
5. Find whether the vectors are parallel,
(-2,1,-1) and (0,3,1)
a) Parallel
b) Collinearly parallel
c) Not parallel
d) Data insufficient
14.
The
unit
vector
to
the
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
6.
a)
b)
c)
d)
Lorentz force is based on,
Dot product
Cross product
Both dot and cross product
Independent of both
15. The polar form of Cartesian coordinates
is
a) Circular coordinates
b) Spherical coordinates
c) Cartesian coordinates
d) Space coordinates
7.
a)
b)
c)
d)
Electromagnetic forces are defined by
Fleming’s right hand rule
Fleming’s left hand rule
Faraday’s law
Ampere law
points
16. The work-electric field relation is
given by
a) Volume integral
b) Surface integral
c) Line integral
d) Relation impossible
Bohol Island State University Main Campus
College of Engineering Architecture and Industrial Design
EE02
Electromagnetics
Activity 1.1
Introduction to Electromagnetics
17. The distance vector can be used to
compute which of the following?
a) Dot product
b) Cross product
c) Unit normal vector
d) Area
27. 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
18. Distance and position vectors rely on
field strength. State True/False.
a) True
b) False
28. The magnetic field intensity is said to
be
a) Divergent
b) Curl free
c) Solenoidal
d) Rotational
19. Find the projection of A on B. Given A
= 10j + 3k and B = 4j + 5k.
a) 6
b) 6.25
c) 6.5
d) 6.75
20. The vector product of two vectors is
given by area of the parallelogram. State
True/False.
a) True
b) False
21. The del operator is called as
a) Gradient
b) Curl
c) Divergence
d) Vector differential operator
22. The relation between vector potential
and field strength is given by
a) Gradient
b) Divergence
c) Curl
d) Del operator
23. The Laplacian operator is actually
a) Grad(Div V)
b) Div(Grad V)
c) Curl(Div V)
d) Div(Curl V)
24. The divergence of curl of a vector is
zero. State True or False.
a) True
b) False
25. The curl of gradient of a vector is
non-zero. State True or False.
a) True
b) False
26. Identify the
a) i . i = j . j
b) i X j = j X k
c) Div (u X v) =
d) i . j = j . k
correct vector identity.
= k . k = 0
= k X i = 1
v . Curl(u) – u . Curl(v)
= k . i = 1
29. 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
30. 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
31. Coulomb is the unit of which quantity?
a) Field strength
b) Charge
c) Permittivity
d) Force
32. Coulomb law is employed in
a) Electrostatics
b) Magnetostatics
c) Electromagnetics
d) Maxwell theory
33. Find the force between
separated by a distance 1m
newton).
a) 18 X 106
b) -18 X 106
c) 18 X 10-6
d) -18 X 10-6
34. Two
What is
a) Away
b) Away
c) From
d) From
2C
in
and
air
-1C
(in
charges 1C and -4C exists in air.
the direction of force?
from 1C
from -4C
1C to -4C
-4C to 1C
Bohol Island State University Main Campus
College of Engineering Architecture and Industrial Design
EE02
Electromagnetics
Activity 1.1
Introduction to Electromagnetics
35. Find the force of interaction between
60 stat coulomb and 37.5 stat coulomb
spaced
7.5cm
apart
in
transformer
oil(εr=2.2) in 10-4 N,
a) 8.15
b) 5.18
c) 1.518
d) 1.815
36. Find the force between two charges when
they are brought in contact and separated
by 4cm apart, charges are 2nC and -1nC, in
μN.
a) 1.44
b) 2.44
c) 1.404
d) 2.404
37. The Coulomb law is an implication of
which law?
a) Ampere law
b) Gauss law
c) Biot Savart law
d) Lenz law
38. Two small diameter 10gm dielectric
balls can slide freely on a vertical
channel. Each carry a negative charge of
1μC. Find the separation between the balls
if the lower ball is restrained from
moving.
a) 0.5
b) 0.4
c) 0.3
d) 0.2
39. A charge of 2 X 10-7 C is acted upon by
a force of 0.1N. Determine the distance to
the other charge of 4.5 X 10-7 C, both the
charges are in vacuum.
a) 0.03
b) 0.05
c) 0.07
d) 0.09
40. 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
41. 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
42. Find the force on a charge 2C in a field
1V/m.
a) 0
b) 1
c) 2
d) 3
43. Find the electric field intensity of
two charges 2C and -1C separated by a
distance 1m in air.
a) 18 X 109
b) 9 X 109
c) 36 X 109
d) -18 X 109
44. What is the electric field intensity at
a distance of 20cm from a charge 2 X 10-6
C in vacuum?
a) 250,000
b) 350,000
c) 450,000
d) 550,000
45. Determine the charge that produces an
electric field strength of 40 V/cm at a
distance of 30cm in vacuum (in 10-8C)
a) 4
b) 2
c) 8
d) 6
46. The field intensity of a charge defines
the impact of the charge on a test charge
placed at a distance. It is maximum at d =
0cm and minimises as d increases. State
True/False
a) True
b) False
47. Electric field of an infinitely long
conductor of charge density λ, is given by
E = λ/(2πεh).aN. State True/False.
a) True
b) False
48. Electric field intensity
infinite sheet of charge σ is
a) Zero
b) Unity
c) σ/ε
d) σ/2ε
due
to
49. For a test charge placed at infinity,
the electric field will be
a) Unity
b) +∞
c) Zero
d) -∞
Bohol Island State University Main Campus
College of Engineering Architecture and Industrial Design
EE02
Electromagnetics
Activity 1.1
Introduction to Electromagnetics
50. In electromagnetic waves, the electric
field will be perpendicular to which of the
following?
a) Magnetic field intensity
b) Wave propagation
c) Both H and wave direction
d) It propagates independently
57. A uniform surface charge of σ = 2 μC/m2,
is situated at z = 2 plane. What is the
value of flux density at P(1,1,1)m?
a) 10-6
b) -10-6
c) 106
d) -106
51. The lines of force are said to be
a) Real
b) Imaginary
c) Drawn to trace the direction
d) Not significant
58. Find the flux density of line charge of
radius (cylinder is the Gaussian surface)
2m and charge density is 3.14 units?
a) 1
b) 0.75
c) 0.5
d) 0.25
52. 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
53. 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
54. 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
55. The Gaussian surface is
a) Real boundary
b) Imaginary surface
c) Tangential
d) Normal
56. Find the flux density of a sheet of
charge density 25 units in air.
a) 25
b) 12.5
c) 6.25
d) 3.125
59. If the radius of a sphere is 1/(4π)m
and the electric flux density is 16π units,
the total flux is given by,
a) 2
b) 3
c) 4
d) 5
60. Find the electric field intensity of
transformer oil (εr = 2 approx) with
density 1/4π (in 109 units)
a) 2.5
b) 3.5
c) 4.5
d) 5.5
61. Divergence theorem is based on
a) Gauss law
b) Stoke’s law
c) Ampere law
d) Lenz law
62. The Gaussian surface for a line charge
will be
a) Sphere
b) Cylinder
c) Cube
d) Cuboid
63. The Gaussian surface for a point charge
will be
a) Cube
b) Cylinder
c) Sphere
d) Cuboid
64. A circular disc of radius 5m with a
surface charge density ρs = 10sinφ is
enclosed by surface. What is the net flux
crossing the surface?
a) 3
b) 2
c) 1
d) 0
Bohol Island State University Main Campus
College of Engineering Architecture and Industrial Design
EE02
Electromagnetics
Activity 1.1
Introduction to Electromagnetics
65. The total charge of a surface with
densities 1,2,…,10 is
a) 11
b) 33
c) 55
d) 77
73. If V = 2x2y – 5z, find its electric
field at point (-4,3,6)
a) 47.905
b) 57.905
c) 67.905
d) 77.905
66. The work done by a charge of 10μC with
a potential 4.386 is (in μJ)
a) 32.86
b) 43.86
c) 54.68
d) 65.68
74. Find the potential between two points
p(1,-1,0) and q(2,1,3) with E = 40xy i +
20x2 j + 2 k
a) 104
b) 105
c) 106
d) 107
67. The potential of a coaxial cylinder
with charge density 1 unit , inner radius
1m and outer cylinder 2m is (in 109)
a) 12.74
b) 13.47
c) 12.47
d) 13.74
68. Find the potential due to a charged
ring of density 2 units with radius 2m and
the point at which potential is measured is
at a distance of 1m from the ring.
a) 18π
b) 24π
c) 36π
d) 72π
69. Gauss law cannot be used to find which
of the following quantity?
a) Electric field intensity
b) Electric flux density
c) Charge
d) Permittivity
70. Gauss
by
a) Div(E)
b) Div(B)
c) Div(H)
d) Div(D)
law for magnetic fields is given
=
=
=
=
0
0
0
0
71. An electric field is given as E = 6y2z
i + 12xyz j + 6xy2 k. An incremental path
is given by dl = -3 i + 5 j – 2 k mm. The
work done in moving a 2mC charge along the
path if the location of the path is at
p(0,2,5) is (in Joule)
a) 0.64
b) 0.72
c) 0.78
d) 0.80
72. The integral form of potential and
field relation is given by line integral.
State True/False
a) True
b) False
75. Find the potential between a(-7,2,1)
and b(4,1,2). Given E = (-6y/x2 )i + ( 6/x)
j + 5 k.
a) -8.014
b) -8.114
c) -8.214
d) -8.314
76. The potential of a uniformly charged
line with density λ is given by,
λ/(2πε) ln(b/a). State True/False.
a) True
b) False
77. A field in which a test charge around
any closed surface in static path is zero
is called
a) Solenoidal
b) Rotational
c) Irrotational
d) Conservative
78. The potential in a lamellar field is
a) 1
b) 0
c) -1
d) ∞
79. Line integral is used to calculate
a) Force
b) Area
c) Volume
d) Length
80. The energy stored in the inductor 100mH
with a current of 2A is
a) 0.2
b) 0.4
c) 0.6
d) 0.8
Bohol Island State University Main Campus
College of Engineering Architecture and Industrial Design
EE02
Electromagnetics
Activity 1.1
Introduction to Electromagnetics
81. The divergence of a vector is a scalar.
State True/False.
a) True
b) False
82.
The
divergence
concept
can
be
illustrated using Pascal’s law. State
True/False.
a) True
b) False
83. Compute the divergence of the vector xi
+ yj + zk.
a) 0
b) 1
c) 2
d) 3
84. Find the divergence of the vector yi +
zj + xk.
a) -1
b) 0
c) 1
d) 3
85. Given D = e-xsin y i – e-xcos y j
Find divergence of D.
a) 3
b) 2
c) 1
d) 0
86. 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)
87. Determine the divergence of F = 30 i +
2xy j + 5xz2 k at (1,1,-0.2) and state the
nature of the field.
a) 1, solenoidal
b) 0, solenoidal
c) 1, divergent
d) 0, divergent
88. 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
89. Find the divergence of the field, P =
x2yz i + xz k
a) xyz + 2x
b) 2xyz + x
c) xyz + 2z
d) 2xyz + z
90. 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
91. Potential difference is the work done
in moving a unit positive charge from one
point to another in an electric field.
State True/False.
a) True
b) False
92. A point charge 2nC is located at
origin. What is the potential at (1,0,0)?
a) 12
b) 14
c) 16
d) 18
93. Six equal point charges Q = 10nC are
located at 2,3,4,5,6,7m. Find the potential
at origin.
a) 140.35
b) 141.35
c) 142.35
d) 143.35
94. A point charge 0.4nC is located at (2,
3, 3). Find the potential differences
between (2, 3, 3)m and (-2, 3, 3)m due to
the charge.
a) 2.5
b) 2.6
c) 2.7
d) 2.8
95. Find the potential of V = 60sin θ/r2 at
P(3,60,25)
a) 5.774
b) 6.774
c) 7.774
d) 8.774
96. Given E = 40xyi + 20x2j + 2k. Calculate
the potential between two points (1,-1,0)
and (2,1,3).
a) 105
b) 106
c) 107
d) 108
97. The potential difference in an open
circuit is
a) Zero
b) Unity
c) Infinity
d) Circuit does not exist open
Bohol Island State University Main Campus
College of Engineering Architecture and Industrial Design
EE02
Electromagnetics
Activity 1.1
Introduction to Electromagnetics
98. The potential taken between two points
across a resistor will be
a) Positive
b) Negative
c) Zero
d) Infinity
99. What is the potential difference
between 10sinθcosφ/r2 at A(1,30,20) and
B(4,90,60)?
a) 2.386
b) 3.386
c) 4.386
d) 5.386
100. The voltage at any point in an ac
circuit will be
a) Peak voltage
b) RMS voltage
c) Average voltage
d) Source voltage