If a source of electromagnetic radiation having power 15 kW produces 10¹⁶ photons per second, the radiation belongs to a part of spectrum is. (Take Planck constant $\left.\mathrm{h}=6\times {10}^{-34}\mathrm{Js}\right)$

Given 15kW power produces 10¹⁶ photons per second. 

Energy for ejecting each photon be E.

$\therefore \mathrm{P}=\frac{\mathrm{N}\times \mathrm{E}}{\mathrm{t}}$

$\Rightarrow \mathrm{E}=\frac{15\times {10}^3}{{10}^{16}}=15\times {10}^{-13}\mathrm{J}$

We know from Planck's equation 

$\mathrm{E} = \mathrm{hf}$

$\Rightarrow \mathrm{f}=\frac{15\times {10}^{-13}}{6\times {10}^{34}}=2.5\times {10}^{21}\mathrm{Hz}$

$\Rightarrow \mathrm{Gamma} \text{rays }$