A hypothetical electromagnetic wave is shown in Fig. 2.2. Find out the wavelength of the radiation.

Wavelength can be defined as the distance between two alike successive points in a wave (usually b/w two maxima s i.e. peaks or two minima s i.e. troughs shown in the fig.)

So, for the given hypothetical wave, wavelength λ = 4 X 2.16 pm

= 8.64 pm.