Question

Electric field in a plane electromagnetic wave is given by $E =50 \sin \left(500 x -10 \times 10^{10} t \right) \,V / m$ The velocity of electromagnetic wave in this medium is :
(Given $C =$ speed of light in vacuum)

• A. $\frac{3}{2} C$
• B. $C$
• C. $\frac{2}{3} C$
• D. $\frac{ C }{2}$

Answer 1

Answer: (C)

$V =\frac{\omega}{ K }=\frac{10 \times 10^{10}}{500}$
$=2 \times 10^{8}$
$V =\frac{2 C }{3}$