Question

A plane electromagnetic wave propagating in the x-direction has wavelength of `60` mm. The electric field is in the y-direction and its maximum magnitude is `33 V//m^(-1)`.The equation for the electric field as function of x and t is:
A. `11 sin pi(t-x//c)`
B. `33 sin pixx10^(11) (t-x//c)`
C. `33 sin pi(t-x//c)`
D. `11 sin pixx10^(11)(t-x//c)`

Answer 1

Correct Answer - b
`omega=2piv=(2pic)/(lambda)=(2pixx3xx10^(8))/(6xx10^(-3))=pixx10^(11) rad//s`
The equation for the electric field, along y-axis in the electromagnetic wave is
`E_(y)=E_(0) sin omega(t-(x)/(c))`
`=33 sin pixx5 10^(11)(t-x//c)`