Give the range of wavelength of visible light.

Which one of the following has the minimum wavelength?

The wavelengths of Gamma rays,$X$-rays,and microwaves are respectively $\lambda_r, \lambda_x$,and $\lambda_m$. Then which of the following relations is correct?

$A$ monochromatic source of light operating at $15 \text{ kW}$ emits $2.5 \times 10^{22} \text{ photons/s}$. The region of an electromagnetic spectrum to which the emitted electromagnetic radiation belongs to . . . . . . . (Take $h = 6.6 \times 10^{-34} \text{ J}\cdot\text{s}$ and $c = 3 \times 10^8 \text{ m/s}$).

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

Pick out the longest wavelength from the following types of radiations.