Practice portal › Electromagnetic Waves › Energy Density of an EM Wave
Asked in JEE Main 10th April 1st Shift 2023 · Instantaneous and average energy density
u = 1/2ε₀E² + B²/2μ₀ with E = E₀ sin(ω t - kx), so u ∝ sin²(ω t - kx)
sin²θ = (1 - cos 2θ)/2, so u oscillates at angular frequency 2ω
That is twice the frequency of the wave itself
Reading this solution needs no sign-in. You only sign in to practise against the clock and keep your progress.
Practise this with a timer