Em Waves Question 130
Question: Find the average energy density corresponding to maximum electric field, if magnetic field in a plane electromagnetic wave is given by $ B=200\times {{10}^{-6}},\sin ,[(4\times 10^{15})(t-x/c)] $
Options:
A) $ 1.6,J,{{m}^{-3}} $
B) $ 0.16,J,{{m}^{-3}} $
C) $ 0.016,J,{{m}^{-3}} $
D) $ 0.0016,J,{{m}^{-3}} $
Show Answer
Answer:
Correct Answer: C
Solution:
[c] Average energy density corresponding to maximum electric field, $ u _{av}=\frac{B _{0}^{2}}{2{\mu _{0}}}=\frac{{{(200\times {{10}^{-6}})}^{2}}}{2\times 4\pi \times {{10}^{-7}}}\cong 0.016,J{{m}^{-3}} $
BETA
