Question

The refractive index of glass is $1.5$ for light waves of $\lambda =2000A^0$ in a vacuum. Its wavelength in glass is then

• A. $2000A^0$
• B. $4000A^0$
• C. $1000A^0$
• D. $3000A^0$

Answer 1

The correct option is B $4000A^0$

Given: The refractive index lof the medium is $1.5$.

The wavelength of the incident light is $2000A^o$.

The wavelenth of the light as it pass through the glass is given by:

$\mu =\frac{c}{v}=\frac{{\lambda }_v}{{\lambda }_g}$

${\lambda }_g=\frac{{\lambda }_v}{1.5}$

$\Rightarrow \frac{6000}{1.5}=4000A^o$