Write the source of ultraviolet waves.

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

List-$I$ ($EM$ Wave)	List-$II$ (Wavelength Range)
$(A)$ Infrared	$(i)$ $ < 10^{-3} \, nm$
$(B)$ Ultraviolet	$(ii)$ $400 \, nm$ to $1 \, nm$
$(C)$ $X$-rays	$(iii)$ $1 \, mm$ to $700 \, nm$
$(D)$ Gamma rays	$(iv)$ $1 \, nm$ to $10^{-3} \, nm$

Choose the correct answer from the options given below:

Which of the following electromagnetic waves has the shortest wavelength?

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R.$
Assertion $A:$ $EM$ waves used for optical communication have longer wavelengths than that of microwaves employed in $RADAR$ technology.
Reason $R:$ Infrared $EM$ waves are more energetic than microwaves (used in $RADAR$).
In the light of the given statements,choose the correct answer from the options given below:

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

The electromagnetic oscillator used in a microwave oven produces electromagnetic waves with a wavelength in the range of ......