The wavelengths of short radio waves,$X$-rays,and ultraviolet waves are $\lambda_{1}$,$\lambda_{2}$,and $\lambda_{3}$ respectively. Arrange them in decreasing order.

How are infrared waves produced?

Infrared radiations are detected by:

Which rays are not a portion of the electromagnetic spectrum?

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

Given below are some famous numbers associated with electromagnetic radiations in different contexts in physics. State the part of the electromagnetic spectrum to which each belongs.
$(a)$ $21 \; cm$ (wavelength emitted by atomic hydrogen in interstellar space).
$(b)$ $1057 \; MHz$ (frequency of radiation arising from two close energy levels in hydrogen; known as Lamb shift).
$(c)$ $2.7 \; K$ (temperature associated with the isotropic radiation filling all space; thought to be a relic of the 'big-bang' origin of the universe).
$(d)$ $5890 \; \mathring{A} - 5896 \; \mathring{A}$ (double lines of sodium).
$(e)$ $14.4 \; keV$ (energy of a particular transition in $^{57}Fe$ nucleus associated with a famous high-resolution spectroscopic method, Mossbauer spectroscopy).