Which of the following is an electromagnetic wave?

Electromagnetic radiation of highest frequency is

Which of the following radiations has the least wavelength?

Match List-$I$ (Wavelength range of electromagnetic spectrum) with List-$II$ (Method of production of these waves) and select the correct option from the options given below the lists:

List-$I$	List-$II$
$(1)$ $700\, nm$ to $1\, mm$	$(i)$ Vibration of atoms and molecules
$(2)$ $1\, nm$ to $400\, nm$	$(ii)$ Inner shell electrons in atoms moving from one energy level to a lower level
$(3)$ $< 10^{-3}\, nm$	$(iii)$ Radioactive decay of the nucleus
$(4)$ $1\, mm$ to $0.1\, m$	$(iv)$ Magnetron valve

In a microwave oven,which type of waves are used?

The frequency range from $3\, MHz$ to $30\, MHz$ is known as: