Pick out the longest wavelength from the following types of radiations.

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

The following table presents parts of the electromagnetic spectrum and their corresponding major applications.

Part of the electromagnetic spectrum	Applications
$P$. Microwave	$I$. For purifying the water
$Q$. $UV$ rays	$II$. For warming the food
$R$. Gamma rays	$III$. For $AM$ and $FM$ communication systems
$S$. Radio wave	$IV$. For treating the cancer cells

The correct option is:

The magnetic field in a plane electromagnetic wave is given by $B = 2 \times 10^{-7} \sin(0.5 \times 10^3 x + 1.5 \times 10^{11} t)$. This electromagnetic wave is .........

Microwaves are used in

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

List-$I$ (Electromagnetic waves)	List-$II$ (Use)
$(a)$ $UV$ rays	$(i)$ Diagnostic tool in medicine
$(b)$ $X-$rays	$(ii)$ Water purification
$(c)$ Microwave	$(iii)$ Communication,Radar
$(d)$ Infrared wave	$(iv)$ Improving visibility in foggy days

Choose the correct answer from the options given below: