Give the range of wavelength of the electromagnetic waves visible to us.

Name the region just beyond (i) the red end and (ii) the violet end, of the spectrum.

Name the radiations of wavelength just (a) longer than 8 x 10^-7 m, (b) shorter than 4 x 10^-7 m

Name the material of prism required for obtaining the spectrum of (a) ultraviolet light, (b) infrared radiations.