The magnetic field in a plane electromagnetic wave is given by $B = 2 \times 10^{-7} \sin(0.5 \times 10^3 x + 1.5 \times 10^{11} t)$. This electromagnetic wave is .........

Write the sources of visible rays and ultraviolet rays and their uses.

What is the correct order of frequency for $\gamma-$ rays $(b)$,$X-$ rays $(a)$,and $UV-$ rays $(c)$?

$(i)$ The wavelength of microwaves is greater than that of $UV$-rays.
$(ii)$ The wavelength of $IR$ rays is less than that of $UV$-rays.
$(iii)$ The wavelength of microwaves is lesser than that of $IR$ rays.
$(iv)$ Gamma rays have the shortest wavelength in the electromagnetic spectrum.
Of the above statements:

If a source of $4 \ kW$ power emits $10^{20}$ photons/second,then this radiation belongs to which part of the electromagnetic spectrum?

The electromagnetic waves with wavelengths $10^7 \ m$,$10^{-10} \ m$,and $10^{-7} \ m$ belong to which categories respectively?