Question

The instantaneous magnitudes of the electric field $(E)$ and the magnetic field $(B)$ vectors in an electromagnetic wave propagating in vacuum are related as

• A. $E=\frac{B}{c}$
• B. $E=c B$
• C. $E=\frac{B}{c^{2}}$
• D. $E=c^{2} B$

Answer 1

Answer: (B)

At every instant the ratio of the magnitude of the electric field to that of the magnetic field in an electromagnetic wave equals the speed of light.