What are called heat waves?

The energy of a gamma $(\gamma)$ ray photon is $E_{\gamma}$,and that of an $X$-ray photon is $E_{X}$. If the visible light photon has an energy of $E_{v}$,then we can say that:

If a source of electromagnetic radiation having power $15 \text{ kW}$ produces $10^{16}$ photons per second,the radiation belongs to which part of the spectrum? (Take Planck constant $h = 6 \times 10^{-34} \text{ Js}$)

Which of the following groups of electromagnetic waves is in increasing order of frequency?

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

Write the source of ultraviolet waves.