Question

In a radio wave if \(E_0 = 10^{-4} \) V/m, then the magnitude of magnetic field and pointing vector is:

• A. \( 3.3 \times 10^{-13} W/m^2, 1.3 \times 10^{-11} W/m^2 \)
• B. \( 10^{-4} W/m^2, 1.3 \times 10^{-11} W/m^2 \)
• C. \( 3.3 \times 10^{-13} W/m^2, 1.3 \times 10^{11} W/m^2 \)
• D. \( 3.3 \times 10^{11} W/m^2, 1.3 \times 10^{-11} W/m^2 \)

Hint:

The Poynting vector represents the power flow in an electromagnetic wave.

Answer 1

The Correct Option is A

The magnitude of the magnetic field \( B_0 \) is related to \( E_0 \) as:
\[ B_0 = \frac{E_0}{c} \] And the Poynting vector magnitude is:
\[ S = \frac{E_0^2}{\mu_0 c} \] Substituting the given values, we find the correct values.