List of top Physics Questions on Ray optics and optical instruments asked in OJEE

A light ray going from air is incident (as shown in figure) at one end of a glass fibre (refractive index $\mu = 1.5$) making an incidence angle of $60^\circ$ on the lateral surface,

so that it undergoes a total internal reflection. How much time would it take to traverse the straight fibre of length 1 km?

When white light passes through a glass prism, one gets spectrum on the other side of the prism. In the emergent beam, the ray which is deviating least is

An object is placed at a distance of $40\, cm$ in front of a concave mirror of focal length $20\, cm$. The nature of image is