2020 Phase-2 Electromagnetic WavesEM wave equation - wave number and wavelength Medium Question 23 of 49 in Electromagnetic Waves

The magnetic field in a plane electromagnetic wave is given by, $B_y=2\times10^{-7}\sin(\pi\times10^3x+3\times10^{11}t)$ T. Calculate the wavelength.

A $\pi\times10^{-3}$ m
B $\pi\times10^3$ m
C $2\times10^{-3}$ m
D $2\times10^3$ m

The answer is C.

Solution

Comparing with $B_y=B_0\sin(kx+\omega t)$, $k=\pi\times10^3\ rad/m$. Wavelength $\lambda=\dfrac{2\pi}{k}=\dfrac{2\pi}{\pi\times10^3}=2\times10^{-3}$ m.

Concept EM wave equation - wave number and wavelength

Electromagnetic Waves in past papers

49 questions from this chapter have appeared across 24 exam years.