Electromagnetic Theory-Scalar and Vector Potentials (CSIR Physical Sciences): Questions 7 - 9 of 10

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Question number: 7

» Electromagnetic Theory » Scalar and Vector Potentials

Appeared in Year: 2012

MCQ▾

Question

The vector potential A due to a magnetic moment m at a point r is given by A=m×rr3 . If m is directed along the positive z – axis, the x – component of the magnetic field, at the point r , is – (June)

Choices

Choice (4) Response

a.

3myzr5

b.

3mxzr5

c.

3mxyr5

d.

3m(z2xy)r5

Question number: 8

» Electromagnetic Theory » Scalar and Vector Potentials

Appeared in Year: 2012

MCQ▾

Question

Consider an infinite conducting sheet in the XY – plane with a time dependent current density Kti^ , where K is constant. The vector potential at (x,y,z) is given by A=μ0K4c(ctz)2i^ . The magnetic field B is –

(December)

Choices

Choice (4) Response

a.

μ0Kz2cj^

b.

μ0K2c(ctz)j^

c.

μ0K2c(ctz)i^

d.

μ0Kt2j^

Question number: 9

» Electromagnetic Theory » Scalar and Vector Potentials

Appeared in Year: 2011

MCQ▾

Question

A constant electric current I in an infinitely long straight wire is suddenly switched on at t=0 . The vector potential at a perpendicular distance r from the wire is given by A=k^μ0I2πln[1r(ct+c2t2r2)] . The electric field at a distance r(<ct) is –

(December)

Choices

Choice (4) Response

a.

cμ0I2πc2t2r212(i^j^)

b.

μ0I2πt12(i^j^)

c.

0

d.

cμ0I2πc2t2r2k^

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