Directions: Each of the next items consists of two statements, one labeled as the `Assertion (A)' and the other as 'Reason (R)' You are to examine these two statements carefully and select the answers to these items using the codes given below :Assertion (A) : For time varying field the relation E̅ = - ∇̅ V is inadequate. Reason (R): Faraday's law states that for time-varying field ∇̅ × E̅ = 0.

Both A and R are individually true and R is the correct explanation of A

Both A and R are individually true but R is not the correct explanation of A

Poisson’s equation is derived with the following assumption about the medium. The medium is:

Non-homogeneous and non-isotropic

Maxwell’s equations of Electromagnetics are not applicable to

Medium moving with respect to system of coordinates

One of the following is not Maxwell’s equation

\(\nabla \times \bar E =- \frac{{\partial \bar B}}{{\partial t}}\)

\(\nabla \times \bar H = \frac{{\partial \bar D}}{{\partial t}} + \bar J\)

Directions : Each of the next items consists of two statements, one labelled as the `Assertion (A)' and the other as 'Reason (R)' You are to examine these two statements carefully and select the answers to these items using the codes given below :Assertion (A): The ratio of the tangential components of current density at two sides of an interface are equal to the conductivities.Reason (R): The- normal component of current density is continuous.

Both A and R are individually true and R is the correct explanation of A

Both A and R are individually true but R is not the correct explanation of A

In a coaxial transmission line (εr = 1), the electric field intensity is given by:\(E = \frac{{100}}{\rho }\cos \left( {{{10}^9}t - 6z} \right){u_p}V/m\)The displacement current density is:

\( - \frac{{216}}{\rho }\cos \left( {{{10}^9}t - 6z} \right){u_p}A/{m^2}\)

\( - \frac{{100}}{\rho }\sin \left( {{{10}^9}t - 6z} \right){u_p}A/{m^2}\)

\(\frac{{116}}{\rho }\sin \left( {{{10}^9}t - 6z} \right){u_p}A/{m^2}\)

\( - \frac{{0.9}}{\rho }\sin \left( {{{10}^9}t - 6z} \right){u_p}A/m\)

\( - \frac{{216}}{\rho }\cos \left( {{{10}^9}t - 6z} \right){u_p}A/{m^2}\)

Maxwell’s major contribution to EM theory was to assert

that a magnetic field varying with time gives rise to an electric field

that an electric field varying with time in free space gives rise to a current

that a magnetic field varying with time gives rise to an electric field

that a magnetic field varying with space gives rise to an electric field

that energy density due to an electric field is \(\frac{1}{2}\varepsilon {E^2}\)

16 + Mcqs in Maxwell'S Equations in Electromagnetic Theory Page 1 McqOptions

1.	A square coil of 20 cm side and with 200 turns is rotated at a uniform velocity of 10 m/s about an axis at right angles to a uniform magnetic field having a flux density of 0.5 T. Determine the instantaneous value of the induced emf when the plane of the coil is in the plane of the field.
A.	400 V
B.	0 V
C.	362 V
D.	200 V
Answer» E.

Discussion

2.	An instrument always extracts some energy from the measured medium. Thus the measured quantity is always disturbed by the act of measurement, which makes a perfect measurement theoretically impossible and it is due to
A.	Skin effect
B.	Inductive effect
C.	Loading effect
D.	Lorenz effect
Answer» D. Lorenz effect

Discussion

3.	Directions: Each of the next items consists of two statements, one labeled as the `Assertion (A)' and the other as 'Reason (R)' You are to examine these two statements carefully and select the answers to these items using the codes given below :Assertion (A) : For time varying field the relation E̅ = - ∇̅ V is inadequate. Reason (R): Faraday's law states that for time-varying field ∇̅ × E̅ = 0.
A.	Both A and R are individually true and R is the correct explanation of A
B.	Both A and R are individually true but 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» D. A is false but R is true

Discussion

4.	Poisson’s equation is derived with the following assumption about the medium. The medium is:
A.	Non-homogeneous and isotropic
B.	Non-homogeneous and non-isotropic
C.	Homogeneous and non-isotropic
D.	Homogeneous and isotropic
Answer» E.

Discussion

5.	Consider \(\vec D = (10x{\hat a_x} - 4y{\hat a_y} + kz{\hat a_z}~)\frac{{\mu C}}{{{m^2}}}\) and \(\vec B = 2{\hat a_y}~mT\). To satisfy the Maxwell’s equation for region σ = 0 and ρv = 0, the value of k will be
A.	– 8 μC/m3
B.	– 6 μC/ m3
C.	– 4 μC/ m3
D.	– 2 μC/ m3
Answer» C. – 4 μC/ m3

Discussion

6.	Maxwell’s equations of Electromagnetics are not applicable to
A.	Isotropic media
B.	Non homogeneous media
C.	Medium moving with respect to system of coordinates
D.	Non linear media
Answer» D. Non linear media

Discussion

7.	In a telephone receiver, the size of each of the two poles is 1.2 cm × 0.2 cm, and the flux between each pole and the diaphragm is 3 × 10-6 Wb. The force attracted to the poles will be nearly
A.	0.15 N
B.	0.20 N
C.	0.30 N
D.	0.40 N
Answer» B. 0.20 N

Discussion

8.	∇ × H = J is differential form of
A.	Gauss’ law
B.	Ampere’s circuital law
C.	Poisson’s equation
D.	Laplace’s equation
Answer» C. Poisson’s equation

Discussion

9.	One of the following is not Maxwell’s equation
A.	∇ ⋅ D = Pv
B.	∇ ⋅ B = J
C.	\(\nabla \times \bar E =- \frac{{\partial \bar B}}{{\partial t}}\)
D.	\(\nabla \times \bar H = \frac{{\partial \bar D}}{{\partial t}} + \bar J\)
Answer» C. \(\nabla \times \bar E =- \frac{{\partial \bar B}}{{\partial t}}\)

Discussion

10.	Consider the following statements regarding Maxwell’s equation in differential form:a) For free space: ∇ × H = (σ + jωε) Eb) For free space: ∇ ⋅ D ≃ ρc) For steady current: ∇ × H = Jd) For static electric field: ∇ ⋅ D = ρWhat of the above statements are correct?
A.	a and b
B.	b and c
C.	c and d
D.	d and a
Answer» D. d and a

Discussion

11.	Maxwell equations1. are extension of the works of Gauss, Faraday and Ampere2. help studying the application of electrostatic fields only3. can be written in integral form and point form4. need not be modified depending upon the media involved in the problem.Which of the above statements are correct?
A.	1 and 3
B.	1 and 4
C.	2 and 3
D.	3 and 4
Answer» B. 1 and 4

Discussion

12.	Directions : Each of the next items consists of two statements, one labelled as the `Assertion (A)' and the other as 'Reason (R)' You are to examine these two statements carefully and select the answers to these items using the codes given below :Assertion (A): The ratio of the tangential components of current density at two sides of an interface are equal to the conductivities.Reason (R): The- normal component of current density is continuous.
A.	Both A and R are individually true and R is the correct explanation of A
B.	Both A and R are individually true but 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» C. A is true but R is false

Discussion

13.	In a coaxial transmission line (εr = 1), the electric field intensity is given by:\(E = \frac{{100}}{\rho }\cos \left( {{{10}^9}t - 6z} \right){u_p}V/m\)The displacement current density is:
A.	\( - \frac{{100}}{\rho }\sin \left( {{{10}^9}t - 6z} \right){u_p}A/{m^2}\)
B.	\(\frac{{116}}{\rho }\sin \left( {{{10}^9}t - 6z} \right){u_p}A/{m^2}\)
C.	\( - \frac{{0.9}}{\rho }\sin \left( {{{10}^9}t - 6z} \right){u_p}A/m\)
D.	\( - \frac{{216}}{\rho }\cos \left( {{{10}^9}t - 6z} \right){u_p}A/{m^2}\)
Answer» D. \( - \frac{{216}}{\rho }\cos \left( {{{10}^9}t - 6z} \right){u_p}A/{m^2}\)

Discussion

14.	In an n-turn coil, the flux through each turn 1s (t3- 4t) mWb. The magnitude of the induced e.m.f. in the coil at t = 5s is 7.1 V. The number of turns in the coil is
A.	10
B.	100
C.	121
D.	1000
Answer» C. 121

Discussion

15.	Maxwell’s major contribution to EM theory was to assert
A.	that an electric field varying with time in free space gives rise to a current
B.	that a magnetic field varying with time gives rise to an electric field
C.	that a magnetic field varying with space gives rise to an electric field
D.	that energy density due to an electric field is \(\frac{1}{2}\varepsilon {E^2}\)
Answer» B. that a magnetic field varying with time gives rise to an electric field

Discussion

16.	For equation of continuity which of the following is true (for steady state currents)?
A.	Δ.J̅ = 0
B.	Δ.J̅ = -2
C.	Δ.J̅ = 1
D.	Δ.J̅ = ∞
Answer» B. Δ.J̅ = -2

Discussion

Explore topic-wise MCQs in Electromagnetic Theory.

A square coil of 20 cm side and with 200 turns is rotated at a uniform velocity of 10 m/s about an axis at right angles to a uniform magnetic field having a flux density of 0.5 T. Determine the instantaneous value of the induced emf when the plane of the coil is in the plane of the field.

An instrument always extracts some energy from the measured medium. Thus the measured quantity is always disturbed by the act of measurement, which makes a perfect measurement theoretically impossible and it is due to

Poisson’s equation is derived with the following assumption about the medium. The medium is:

Consider \(\vec D = (10x{\hat a_x} - 4y{\hat a_y} + kz{\hat a_z}~)\frac{{\mu C}}{{{m^2}}}\) and \(\vec B = 2{\hat a_y}~mT\). To satisfy the Maxwell’s equation for region σ = 0 and ρv = 0, the value of k will be

Maxwell’s equations of Electromagnetics are not applicable to

In a telephone receiver, the size of each of the two poles is 1.2 cm × 0.2 cm, and the flux between each pole and the diaphragm is 3 × 10-6 Wb. The force attracted to the poles will be nearly

∇ × H = J is differential form of

One of the following is not Maxwell’s equation

Consider the following statements regarding Maxwell’s equation in differential form:a) For free space: ∇ × H = (σ + jωε) Eb) For free space: ∇ ⋅ D ≃ ρc) For steady current: ∇ × H = Jd) For static electric field: ∇ ⋅ D = ρWhat of the above statements are correct?

In a coaxial transmission line (εr = 1), the electric field intensity is given by:\(E = \frac{{100}}{\rho }\cos \left( {{{10}^9}t - 6z} \right){u_p}V/m\)The displacement current density is:

In an n-turn coil, the flux through each turn 1s (t3- 4t) mWb. The magnitude of the induced e.m.f. in the coil at t = 5s is 7.1 V. The number of turns in the coil is

Maxwell’s major contribution to EM theory was to assert

For equation of continuity which of the following is true (for steady state currents)?