Electromagnetic Spectrum & Atmosphere question from JEE Main 2014 (9 Apr, Shift 1)

Answer: d

1. $700\ \text{nm}$ to $1\ \text{mm}$ is infrared: vibration of atoms and molecules (i).
2. $1\ \text{nm}$ to $400\ \text{nm}$ is ultraviolet: inner-shell electrons moving to a lower level (ii), as given in NCERT.
3. $< 10^{-3}\ \text{nm}$ is gamma rays: radioactive decay of the nucleus (iii).
4. $1\ \text{mm}$ to $0.1\ \text{m}$ is microwaves: magnetron valve (iv).
5. So the answer is (D) (a)-(i), (b)-(ii), (c)-(iii), (d)-(iv).