Em Waves Question 93
Question: A plane electromagnetic wave propagating in the X-direction has wavelength of $ 6.0mm $ . The electric field is in the Y-direction and its maximum magnitude is $ 33V{{m}^{-1}} $ . The equation for the electric field as a function of x and t is
Options:
A) $ 11 \sin \pi ( t-\frac{x}{c} ) $
B) $ 33\sin [ \pi \times 10^{11}( t-\frac{x}{c} ) ] $
C) $ 33\sin \pi ( t-\frac{x}{c} ) $
D) $ 11\sin [ \pi \times 10^{11}( t-\frac{x}{c} ) ] $
Show Answer
Answer:
Correct Answer: B
Solution:
[b] $ \omega =2\pi v=\frac{2\pi c}{\lambda }=\frac{2\pi \times 3\times 10^{8}}{6\times {{10}^{-3}}} $
$ =\pi \times 10^{11} rad/\sec $ The equation for the electric field, along y-axis in the electromagnetic wave is $ Ey=E _{0},\sin ,\omega ( t-\frac{x}{c} )=33\sin [ \pi \times 10^{11}( t-\frac{x}{c} ) ] $
BETA
