Question 139: EM waves

Question

An electromagnetic wave of intensity 50 Wm–2 enters in a medium of refractive index 'n' without any loss. The ratio of the magnitudes of electric, and the ratio of the magnitudes of magnetic fields of the wave before and after entering into the medium are respectively, given by:

Accepted Answer

C $$ = {1 \over {\sqrt {{\mu _0}{ \in _0}} }}$$
V = $$ = {1 \over {\sqrt {k{ \in _0}{\mu _0}} }}$$ [For transparent medium $$\mu $$
r
$$ \approx $$ $$\mu $$
0
]
$$ 	herefore $$  $${C \over V}$$ $$=$$ $$\sqrt k  = $$ n
$${1 \over 2} \in {}_0\,E_0^2$$C $$=$$ intensity $$=$$ $${1 \over 2}$$$$ \in $$
0
kE
2
v
$$ 	herefore $$   E$$_0^2$$C $$=$$ kE
2
v
$$ \Rightarrow $$  $${{E_0^2} \over {{E^2}}} = {{kV} \over C} = {{{n^2}} \over n} \Rightarrow {{{E_0}} \over E} = \sqrt n $$
similarly
$${{B_0^2C} \over {2{\mu _0}}} = {{{B^2}v} \over {2{\mu _0}}} \Rightarrow {{{B_0}} \over B} = {1 \over {\sqrt n }}$$

Answer

$$\left( {{1 \over {\sqrt n }},{1 \over {\sqrt n }}} \right)$$

Answer

$$\left( {\sqrt n ,\sqrt n } \right)$$

Answer

$$\left( {\sqrt n ,{1 \over {\sqrt n }}} \right)$$

Answer

$$\left( {{1 \over {\sqrt n }},\sqrt n } \right)$$

EM waves

An electromagnetic wave of intensity 50 Wm–2 enters in a medium of refractive index 'n' without any loss. The ratio of the magnitudes of electric, and the ratio of the magnitudes of magnetic fields of the wave before and after entering into the medium are respectively, given by:

Choose the correct answer: