A region shown below contains a perfect conducting half-space and

A region shown below contains a perfect conducting half-space and
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A region shown below contains a perfect conducting half-space and air. The surface current \(\overrightarrow {{K_S}} \) on the surface of the perfect conductor is \(\overrightarrow {{K_S}} = \hat x2\) amperes per meter. The tangential \(\vec H_t\) field in the air just above the perfect conductor is

A. (x̂ + ẑ) 2 amperes per meter

B. x̂ 2 amperes per meter

C. –ẑ 2 amperes per meter

D. ẑ 2 amperes per meter

Please scroll down to see the correct answer and solution guide.

Right Answer is: D

SOLUTION

Concept:

The boundary condition for the tangential magnetic field is given by:

\({H_{t1}} - {H_{t2}} = \overrightarrow {{K_s}} \times {\hat a_n}\)

Also, the tangential component of the magnetic field inside a perfect conductor is zero.

Calculation:

Given:

The boundary condition for tangential magnetic field is:

\({H_{{t_1}}} - {H_{{t_2}}} = \overrightarrow {{K_S}} \times {\hat a_n}\)

The tangential component of the magnetic field inside a perfect conductor is zero.

i.e. \({H_{{t_2}}} = 0\) 

\({H_{{t_1}}} = \overrightarrow {{K_S}} \times {\hat a_n} = 2\hat x \times \hat y\)

\({H_{{t_1}}} = 2\hat z\;A/m\)