(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)
(a) : Waves of 700 nm to 1 mm can be produced by vibration of atoms and molecules (b) : Waves of 1 nm to 400 nm are produced when an electron moves from one energy level to lower level in an atom (c) : Waves of wavelength <10⁻¹² nm can be produced by radioactive decay of the nucleus (d) : Waves of 1 mm to 0.1 m are produced by magnetron valve.