Question 100: EM waves

Question

The electric field in an electromagnetic wave is given by E = 56.5 sin $$\omega$$(t $$-$$ x/c) NC
$$-$$1
. Find the intensity of the wave if it is propagating along x-axis in the free space.
(Given : $$\varepsilon $$
0
= 8.85 $$	imes$$ 10
$$-$$12
C
2
N
$$-$$1
m
$$-$$2
)

Accepted Answer

$$I = {1 \over 2}{\varepsilon _0}E_0^2c$$
$$ = {1 \over 2}  8.5 	imes {10^{ - 12}} 	imes {(56.5)^2} 	imes 3 	imes {10^8}$$
$$ = 4.24$$ W/m
2

Answer

5.65 Wm
$$-$$2

Answer

4.24 Wm
$$-$$2

Answer

1.9 $$	imes$$ 10
$$-$$7
Wm
$$-$$2

Answer

56.5 Wm
$$-$$2

EM waves

The electric field in an electromagnetic wave is given by E = 56.5 sin $\omega(t - x/c) NC -1 . Find the intensity of the wave if it is propagating along x-axis in the free space. (Given : \varepsilon 0 = 8.85 \times 10 -12 C 2 N -1 m -$2 )

Choose the correct answer: