The magnetic field of a plane electromagnetic wave is given by B = ( 400 μT ) sin 4 . 0 x 10 15  …

The magnetic field of a plane electromagnetic wave is given by B=(400μT)sin4.0x1015 s-1t-xc Average energy density corresponding to the electric field is
  1. 8×10−3 J m−3
  2. 31.8×10−3J m−3
  3. 80×10−3 J m−3
  4. 3.18×10−3 J m−3

Solution

Average energy density, Uavg=B022μ0

⇒Uavg=400×10-622×4π×10-7

⇒Uavg=16×10-88π×10-7

⇒Uavg=63.66×10-3

Average energy density corresponding to electric field, U=Uavg2=63.66×10-32

⇒U=31.8×10-3 J.m-3

Asked in: AP EAMCET 2021 (19 Aug Shift 2)

Practice more Electromagnetic Waves questions on Aicharya