Question

the plane polarised electromagnetic wave is travelling in free space along +x direction. the amplitude of the electric field is E0= 240 N/c and its frequency is 150 Mhz. the electric field of the wave can be written as

Answer 1

electric field of the wave along positive x direction can be written as
$\boxed{\bf{E=E_0sin(kx-\omega t)}}$

so, first of all, we have to find out k, $\omega$

given, frequency of wave , f = 150MHz
= 150 × 10^6 Hz = 1.5 × 10^8 Hz
so, angular frequency , $\omega$ = 2π × 150 × 10^6
= π × (300) × 10^6 rad/sec
= 3π × 10^8 rad/sec

K = $\frac{\omega}{c}$
c is the speed of light
so, K = 3π × 10^8/3 × 10^8 = π

now, equation of electric field of the wave is
E = 240sin(π x - 3π × 10^8) N/C