Question

The magnetic field of a plane electromagnetic wave is given by B = 2 × 10^-7 sin (0.5 × 10³ x + 1.5 × 10¹¹t)

1. What is the maximum amplitude of this magnetic field?

2. What is wave length and frequency?

3. If this electro magnetic move in z direction. Write the equation of it’s electric field.

Answer 1

1.  2 × 10^-7

2. Comparing with standard equation

B = B_x Sin (kx + ωt)

we get, kx = 0.5 × 10³ x.

\(\frac{2 \pi}{λ }\) = 0.5 x 10³

λ  = \(\frac{2 \pi}{0.5\times10^3}\)

m = 12.56 × 10^-3m
ω = 1.5 × 10¹¹, 2πf = 1.5 × 10¹¹
f = 2.3 × 10¹¹hz

3. Amplitude E₀ = B₀ C
= 2 × 10^-7 × 3 × 10⁸ = 60 N/C
If magnetic field vibrate in x direction, then E_y = 60 sin (0.5 × 10³z + 1.5 × 10¹¹t).