The electric field (in NC−1) in an electromagnetic wave is given by E = 50 sin ω ( t - x/c) . The energy stored in a cylinder of cross-section 10 cm2 and length 100 cm, along the x-axis will be
Answer & explanation
Correct answer: option 2
Energy contained in a cylinder
U = average energy density × volume
$=\frac{1}{2}ε_0E^2_0 ×Al$
$=\frac{1}{2}×(8.85 ×10^{-12}) × (50)^2 ×(10 ×10^{-4}) × 1$
$= 1.1 × 10^{-11} J$