Question

An electromagnetic wave passes through space and its equation is given by E = E₀ sin(ω t - kx). The energy density of the electromagnetic wave in space is:

• A. (1)/(2)₀ E₀²
• B. (1)/(4)₀ E₀²
• C. ₀ E₀²
• D. 2₀ E₀²

Hint:

In electromagnetic waves, electric and magnetic energies are equal.

Answer 1

The Correct Option is A

Step 1: Energy density components. Total energy density is sum of electric and magnetic energy densities.
Step 2: Equality of contributions. Each contributes: (1)/(4)₀ E₀²
Step 3: Total energy density. u = (1)/(2)₀ E₀²