Which of the following radiations has the shortest wavelength?

If an electron oscillates at a frequency of $1 \, GHz$,it emits:

$A$ 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 $c = 3 \times 10^8 \text{ m/s}$).

In household appliances,which waves are used to operate remote control switches?

The approximate height of the ozone layer above the ground is:

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