The frequencies of $X$-rays,$\gamma$-rays,and ultraviolet rays are $a, b$,and $c$ respectively. Which of the following relations is correct?

$(i)$ The wavelength of microwaves is greater than that of $UV$-rays.
$(ii)$ The wavelength of $IR$ rays is less than that of $UV$-rays.
$(iii)$ The wavelength of microwaves is lesser than that of $IR$ rays.
$(iv)$ Gamma rays have the shortest wavelength in the electromagnetic spectrum.
Of the above statements:

Match List-$I$ with List-$II$.

List-$I$	List-$II$
$A$. Microwaves	$I$. Physiotherapy
$B$. $UV$ rays	$II$. Treatment of cancer
$C$. Infra-red rays	$III$. Lasik eye surgery
$D$. $X$-rays	$IV$. Aircraft navigation

Choose the correct answer from the options given below:

What is called as the electromagnetic spectrum?

What is the approximate wavelength range of the electromagnetic spectrum?

Match List-$I$ with List-$II$:

List-$I$	List-$II$
$(a)$ Ultraviolet rays	$(i)$ Study crystal structure
$(b)$ Microwaves	$(ii)$ Greenhouse effect
$(c)$ Infrared waves	$(iii)$ Sterilizing surgical instruments
$(d)$ $X$-rays	$(iv)$ Radar system

Choose the correct answer from the options given below: