Statement (S): Using Huygen's eye-piece measurements can be taken but are not correct.

Reason (R): The cross wires, scale and final image are not magnified proportionately because the image of the objects is magnified by two lenses, whereas the cross wire scale is magnified by one lens only.

Identify the correct one

The adjoining figure represents a wavefront $\mathrm{AB}$ which passes from air to another transparent medium and produces a new wavefront $\mathrm{CD}$ after refraction.

The refractive index of the medium is ($\mathrm{PQ}$ is the boundary between air and the medium)

A ray travels from point $A$ to $\mathrm{B}$ from a rarer to denser medium. Of the four paths shown in the figure, which is the path for the least time?