Question 102: EM waves

Question

A plane electromagnetic wave travels in a medium of relative permeability 1.61 and relative permittivity 6.44. If magnitude of magnetic intensity is 4.5 $$	imes$$ 10
$$-$$2
Am
$$-$$1
at a point, what will be the approximate magnitude of electric field intensity at that point?
(Given : Permeability of free space $$\mu$$
0
= 4$$\pi$$ $$	imes$$ 10
$$-$$7
NA
$$-$$2
, speed of light in vacuum c = 3 $$	imes$$ 10
8
ms
$$-$$1
)

Accepted Answer

H = 4.5 $$	imes$$ 10
$$-$$2
So B = $$\mu$$
0
$$\mu$$H
Thus $$E = {c \over n}B$$ (where n $$\Rightarrow$$ refractive index)
So $$E = {{3 	imes {{10}^8} 	imes 4\pi  	imes {{10}^{ - 7}} 	imes 1.61 	imes 4.5 	imes {{10}^{ - 2}}} \over {\sqrt {1.61 	imes 6.44} }}$$
$$E = 8.48$$

Answer

16.96 Vm
$$-$$1

Answer

2.25 $$	imes$$ 10
$$-$$2
Vm
$$-$$1

Answer

8.48 Vm
$$-$$1

Answer

6.75 $$	imes$$ 10
6
Vm
$$-$$1

EM waves

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