The frequencies of $\gamma$-rays,$X$-rays,and ultraviolet radiations are $B, A,$ and $C$ respectively. Which of the following relations is correct?

$Ultraviolet$ radiations are used in $LASIK$ surgery.

The ozone layer blocks radiation of which wavelength?

Write short information regarding electromagnetic waves.

Electromagnetic waves with wavelength:
$(i)$ ${\lambda _1}$ is used in satellite communication.
$(ii)$ ${\lambda _2}$ is used to kill germs in water purifiers.
$(iii)$ ${\lambda _3}$ is used to detect leakage of oil in underground pipelines.
$(iv)$ ${\lambda _4}$ is used to improve visibility in runways during fog and mist conditions.
$(a)$ Identify and name the part of the electromagnetic spectrum to which these radiations belong.
$(b)$ Arrange these wavelengths in ascending order of their magnitude.
$(c)$ Write one more application of each.

To which region of the electromagnetic spectrum does the frequency $1\, GHz$ correspond?