If the energy of an electromagnetic wave is $14.4 \, keV$,which region of the electromagnetic spectrum does it belong to?

Which of the following represents the wavelength range of infrared rays?

Give the range of wavelength of visible light.

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?

Match the electromagnetic radiations given in List-$I$ with their uses given in List-$II$.
| List-$I$ | List-$II$ |
| :--- | :--- |
| $A$) $X$-rays | $P$) Remote switches |
| $B$) $UV$-rays | $Q$) Finger prints in forensic labs |
| $C$) Radio waves | $R$) Crystal structure study |
| $D$) $IR$-rays | $S$) $TV$ communication system |

Infrared radiation was discovered in $1800$ by