Q. The magnetic field of an Electromagnetic Wave is given by $B_{Y} = 3\ \times 10^{- 7}\ sin\ \left( 10^{3}x + 6.29 \times \ 10^{12}t \right).$ The wavelength of the Electromagnetic Wave is
A) 6.28 cm
B) 3.14 cm
C) 0.63 cm
D) 0.32 cm
Explanation
(c) Given, $B_{y}\ = \ 3\ \times \ 10^{- 7}\sin{(10^{3}x + 6.28\ \times \ 10^{12}t)}.$
Comparing with the general equation
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ B_{y} = B_{0}\sin{(kx + \omega t)}$
we get $k = 10^{3}$
or $\frac{2\pi}{\lambda}$ = 10$^{3}$
$\ \ \Rightarrow \ \ \ \ \ \ \ \ \ \lambda = \frac{2\pi}{10^{3}}$
$= \ 6.28\ \times \ 10^{- 3}m$
$= \ 0.63\ cm$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.