Question

Radio waves and visible light in vacuum have

• A. same velocity but different wavelength
• B. continuous emission spectrum
• C. band absorption spectrum
• D. line emission spectrum

Answer 1

The correct option is A same velocity but different wavelength

$Answer:-$ A

speed of electromagnetic wave in vacuum is given by:-

c(speed of light)=frequency$\times$ wavelength =$\frac{1}{{\mu }_0{ϵ}_0}$=constant

as we go from gamma rays to radio waves frequency decreases and wavelength increases thereby maintaining the product constant.

so velocity is same but wavelength is different.