Question

In the given electromagnetic wave \[ E_y = 600 \sin(\omega t - kx) \, \text{V/m}, \] intensity of the associated light beam is (in W/m$^2$); (Given $\epsilon_0 = 9 \times 10^{-12} \, \text{C}^2 \text{N}^{-1} \text{m}^{-2}$).

• A. 486
• B. 243
• C. 729
• D. 972

Answer 1

The Correct Option is A

The intensity \( I \) of an electromagnetic wave is given by:
\[I = \frac{1}{2} \varepsilon_0 E_0^2 c\]
where \( E_0 = 600 \, \text{Vm}^{-1} \) and \( c = 3 \times 10^8 \, \text{m/s} \).
Substitute the values:
\[I = \frac{1}{2} \times 9 \times 10^{-12} \times (600)^2 \times 3 \times 10^8\]
\[= \frac{9}{2} \times 36 \times 3 = 486 \, \text{W/m}^2\]