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

Electromagnetic waves of wavelength ranging from $100 \text{ Å}$ to $400 \text{ Å}$ come under which region?

Arrange the following electromagnetic radiations per quantum in the order of increasing energy :-
$A$ : Blue light
$B$ : Yellow light
$C$ : $X$-ray
$D$ : Radiowave

The number of wavelengths in the visible spectrum is:

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:

The terminology of different parts of the electromagnetic spectrum is given in the text. Use the formula $E = hv$ (for energy of a quantum of radiation: photon) and obtain the photon energy in units of $eV$ for different parts of the electromagnetic spectrum. In what way are the different scales of photon energies that you obtain related to the sources of electromagnetic radiation?