$A$ thin prism of angle $6^{\circ}$ made of glass of refractive index $1.5$ is combined with another prism made of glass of refractive index $1.75$ to produce dispersion without deviation. Then the angle of the second prism is ...... (in $^{\circ}$)

One face of a glass prism is silver-polished. $A$ light ray falls at an angle of $45^{\circ}$ on the other face. After refraction, it is subsequently reflected from the silvered face and then retraces its path. The refracting angle of the prism is $30^{\circ}$. The refractive index of the prism is:

If a ray of light passes through an equilateral prism such that the angle of incidence and the angle of emergence are both equal to $70 \%$ of the angle of the prism, then the angle of deviation is (in $^{\circ}$)

The angle of minimum deviation for an incident light ray on an equilateral prism is equal to its refracting angle. The refractive index of its material is

Which colour has more speed in a glass prism? Blue or yellow?

The refractive index of a prism is measured using three lines of a mercury vapour lamp. If $\mu_1, \mu_2$ and $\mu_3$ are the measured refractive indices for these green,blue and yellow lines respectively,then