Ncert Exercises & Solutions

8.3 What physical quantity is the same for X-rays of wavelength $10^{- 10}$ m, the red light of wavelength 6800 Å and radiowaves of wavelength 500m?

Hint: Recall the properties of electromagnetic waves.
Step: Identify the speed of X-rays, red light and radiowaves.
The speed of light (

3 \times 10^{8}

m/s) is the same for all wavelengths in vacuum. It is independent of the wavelength.