Test: Magnetic Vector Potential


10 Questions MCQ Test Electromagnetic Fields Theory | Test: Magnetic Vector Potential


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This mock test of Test: Magnetic Vector Potential for Electronics and Communication Engineering (ECE) helps you for every Electronics and Communication Engineering (ECE) entrance exam. This contains 10 Multiple Choice Questions for Electronics and Communication Engineering (ECE) Test: Magnetic Vector Potential (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Magnetic Vector Potential quiz give you a good mix of easy questions and tough questions. Electronics and Communication Engineering (ECE) students definitely take this Test: Magnetic Vector Potential exercise for a better result in the exam. You can find other Test: Magnetic Vector Potential extra questions, long questions & short questions for Electronics and Communication Engineering (ECE) on EduRev as well by searching above.
QUESTION: 1

The magnetic vector potential is a scalar quantity. 

Solution:

Answer: b
Explanation: The magnetic vector potential could be learnt as a scalar. But it is actually a vector quantity, which means it has both magnitude and direction.

QUESTION: 2

Find the magnetic field intensity when the magnetic vector potential x i + 2y j + 3z k.

Solution:

Answer: b
Explanation: The magnetic field intensity is given by H = -Grad(Vm). The gradient of Vm is 1 + 2 + 3 = 6. Thus H = -6 units.

QUESTION: 3

The value of ∫ H.dL will be

Solution:

Answer: b
Explanation: By Stoke’s theorem, ∫ H.dL = ∫ Curl(H).dS and from Ampere’s law, Curl(H) = J. Thus ∫ H.dL = ∫ J.dS which is nothing but current I.

QUESTION: 4

Given the vector potential is 16 – 12sin y j. Find the field intensity at the origin.

Solution:

Answer: c
Explanation: The field intensity is given by H = – Grad(V). The gradient is given by 0 – 12cos y. At the origin, the gradient will be -12 cos 0 = -12. Thus the field intensity will be 12 units.

QUESTION: 5

Find the vector potential when the field intensity 60x2 varies from (0,0,0) to (1,0,0).

Solution:

Answer: b
Explanation: The field intensity H = -Grad(V). To get V, integrate H with respect to the variable. Thus V = -∫H.dl = -∫60x2 dx = -20x3 as x = 0->1 to get -20.

QUESTION: 6

Find the flux density B when the potential is given by x i + y j + z k in air. 

Solution:

Answer: b
Explanation: The field intensity H = -Grad(V). Since the given potential is a position vector, the gradient will be 3 and H = -3. Thus the flux density B = μH = 4π x 10-7 x (-3) = -12π x 10-7 units.

QUESTION: 7

The Laplacian of the magnetic vector potential will be

Solution:

Answer: a
Explanation: The Laplacian of the magnetic vector potential is given by Del2(A) = -μ J, where μ is the permeability and J is the current density.

QUESTION: 8

The magnetic vector potential for a line current will be inversely proportional to

Solution:

Answer: d
Explanation: The magnetic vector potential for the line integral will be A = ∫ μIdL/4πR. It is clear that the potential is inversely proportional to the distance or radius R.

QUESTION: 9

The current element of the magnetic vector potential for a surface current will be

Solution:

Answer: c
Explanation: The magnetic vector potential for the surface integral is given by A = ∫ μKdS/4πR. It is clear that the current element is K dS.

QUESTION: 10

The relation between flux density and vector potential is 

Solution:

Answer: a
Explanation: The magnetic flux density B can be expressed as the space derivative of the magnetic vector potential A. Thus B = Curl(A).

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