Question

Electromagnetic radiation of frequency $n$, wavelength $\lambda$, travelling with velocity $v$ in air, enters a glass slab of refractive index $\mu$. The frequency, wavelength and velocity of light in the glass slab will be respectively.

• A. $\frac{n}{\mu },\frac{\lambda }{\mu },\frac{v}{\mu }$
• B. $n,\frac{\lambda }{\mu },\frac{v}{\mu }$
• C. $n,\lambda ,\frac{v}{\mu }$
• D. $\frac{n}{\mu },\frac{\lambda }{\mu },v$

Answer 1

The correct option is B $n,\frac{\lambda }{\mu },\frac{v}{\mu }$

In going from one medium to another, frequency remains the same but wavelength and velocity decreases with the increase in refractive index, i.e., wavelength becomes ${\lambda }^{\prime }=\frac{\lambda }{\mu }$ and velocity becomes $v=\frac{v}{\mu }$