Question 122: EM waves

Question

The magnetic field of a plane electromagnetic wave is
$\overrightarrow B  = 3 	imes {10^{ - 8}}\sin \left[ {200\pi \left( {y + ct} ight)} ight]\widehat i$ T
where c = 3 $ 	imes $ 10
8
ms
–1
is the speed of light.
The corresponding electric field is :

Accepted Answer

Given, $\overrightarrow B  = 3 	imes {10^{ - 8}}\sin \left[ {200\pi \left( {y + ct} ight)} ight]\widehat i$ T
$ 	herefore $ E
0
= CB
0
= 3 ÃÂ 10
8
ÃÂ 3 ÃÂ 10
Ã¢ÂÂ8
= 9 V/m
We know, $\left( {\overrightarrow E  	imes \overrightarrow B } ight)||\overrightarrow C $
And here $\widehat B = \widehat i\& \widehat C =  - \widehat j$
$ 	herefore $ $\widehat E =  - \widehat k$
So, $\overrightarrow E  =  - 9\sin \left[ {200\pi \left( {y + ct} ight)} ight]\widehat k$ V/m

Answer

$\overrightarrow E  =  - {10^{ - 6}}\sin \left[ {200\pi \left( {y + ct} \right)} \right]\widehat k$ V/m

Answer

$\overrightarrow E  =  - 9\sin \left[ {200\pi \left( {y + ct} \right)} \right]\widehat k$ V/m

Answer

$\overrightarrow E  = 9\sin \left[ {200\pi \left( {y + ct} \right)} \right]\widehat k$ V/m

Answer

$\overrightarrow E  = 3 	imes {10^{ - 8}}\sin \left[ {200\pi \left( {y + ct} ight)} ight]\widehat k$

EM waves

The magnetic field of a plane electromagnetic wave is \overrightarrow B = 3 \times {10^{ - 8}}\sin \left[ {200\pi \left( {y + ct} \right)} \right]\widehat i T where c = 3 \times 10 8 ms –1 is the speed of light. The corresponding electric field is :

Choose the correct answer: