Question

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
(a) \(700\ \mathrm{nm}\) to \(1\ \mathrm{mm}\)	(i) Vibration of atoms and molecules.
(b) \(1\ \mathrm{nm}\) to \(400\ \mathrm{nm}\)	(ii) Inner shell electrons in atoms moving from one energy level to a lower level.
(c) \(\lt 10^{-3}\ \mathrm{nm}\)	(iii) Radioactive decay of the nucleus.
(d) \(1\ \mathrm{mm}\) to \(0.1\ \mathrm{m}\)	(iv) Magnetron valve.

• (a) - (iii), (b) - (iv), (c) - (i), (d) - (ii)
• (a) - (i), (b) - (ii), (c) - (iii), (d) - (iv)
• (a) - (iv), (b) - (iii), (c) - (ii), (d) - (i)
• (a) - (ii), (b) - (iii), (c) - (iv), (d) - (i)

Hint:

Identify each wavelength band (infrared, ultraviolet, gamma, microwave) and recall its source.

Answer 1

The Correct Option is B

(a) 700 nm to 1 mm is the infrared region, produced by vibration of atoms and molecules: (i).
(b) 1 nm to 400 nm is ultraviolet (and soft X-ray edge), produced by transitions of inner-shell electrons to lower levels: (ii).
(c) Wavelengths below \(10^{-3}\) nm are gamma rays, produced in radioactive decay of the nucleus: (iii).
(d) 1 mm to 0.1 m are microwaves, produced by a magnetron (klystron) valve: (iv).
So (a)-(i), (b)-(ii), (c)-(iii), (d)-(iv).
Answer: (2) (a) - (i), (b) - (ii), (c) - (iii), (d) - (iv)