Which of the following electromagnetic waves has the lowest frequency?

Write short information regarding electromagnetic waves.

$X$-rays and gamma rays are both electromagnetic waves. Which of the following statements is true?

$TV$ waves have a wavelength range of $1-10 \, m$. Their frequency range in $MHz$ is

In the following,List $A$ consists of the wavelength range of different $EM$ waves and List $B$ consists of ways to produce them. Match the following lists.
| List $A$ | List $B$ |
| :--- | :--- |
| $A$. $400 \ nm$ to $1 \ nm$ | $1$. Radioactive decay of the nucleus. |
| $B$. $> 0.1 \ nm$ | $2$. Vibration of atoms and molecules. |
| $C$. $1 \ mm$ to $700 \ nm$ | $3$. Rapid acceleration and deceleration of electrons in aerials. |
| $D$. $< 10^{-3} \ nm$ | $4$. Inner shell electrons in atoms moving from one energy level to a lower level. |

The power of a source is $4 \, kW$. If it produces $10^{20}$ photons in $1 \, s$,then the radiation emitted from this source belongs to which part of the electromagnetic spectrum?