The angle of minimum deviation produced by a thin prism in air is $\delta_1$. What will be the minimum deviation ($\delta_2$) if the prism is immersed in liquid ?
$\left[ {}^a n_g = \dfrac{3}{2}, \ {}^a n_\ell = \dfrac{1}{3} \right]$

In the phenomenon of refraction of light for the same angle of incidence

An equiconvex lens of focal length F is cut in to two equal parts along the vertical axis. The focal length of each part will be

A ray of light travels from air to water to glass and again from glass to air. Refractive index of water with respect to air is 'x', glass with respect to water is 'y' and air with respect to glass is 'z'. Which one of the following is correct?