Question

The refractive index of certain glass is $1.5$ for light whose wavelength in vacuum is $6000 \,\mathring{A}$. The wavelength of this light when it passes through glass is:

• A. $4000 \,\mathring{A}$
• B. $6000 \,\mathring{A}$
• C. $9000 \,\mathring{A}$
• D. $15000 \,\mathring{A}$

Answer 1

Answer: (A)

As we know,
$\mu=\frac{ c }{ v } $
$\Rightarrow \frac{ n \lambda_{1}}{ n \lambda_{2}}$
(Frequency remains same in all medias)
$\therefore \mu=\frac{\lambda_{1}}{\lambda_{2}}$
$\lambda_{2}=\frac{6000}{1.5}=4000 \,\mathring{A} $