List of top Physics Questions on Wave Optics asked in IIT JAM PH

Consider a hemispherical glass lens (refractive index is 1.5) having radius of curvature \( R = 12 \, \text{cm} \) for the curved surface. An incoming ray, parallel to the optical axis, is incident on the curved surface at a height \( h = 1 \, \text{cm} \) above the optical axis, as shown in the figure. The distance \( d \) (from the flat surface of the lens) at which the ray crosses the optical axis is ............ cm (Round off to two decimal places). 

A laser beam shines along a block of transparent material of length 2.5 m. Part of the beam goes to the detector \( D_1 \) while the other part travels through the block and then hits the detector \( D_2 \). The time delay between the arrivals of the two light beams is inferred to be 6.25 ns. The speed of light \( c = 3 \times 10^8 \, \text{m/s} \). The refractive index of the block is ............ (Round off to two decimal places). 

The figure shows the cross-section of a hollow cylindrical tank, 2.2 m in diameter, which is half filled with water (refractive index of 1.33). The space above the water is filled with a gas of unknown refractive index. A small laser moves along the bottom surface and aims a light beam towards the center (see figure). When the laser moves a distance of \( S = 1.09\,\text{m} \) or beyond from the lowest point in the water, no light enters the gas. Identify the correct statement(s). (Speed of light = \( 3 \times 10^8\,\text{m/s} \)) 

In the figure below, point A is the object and point B is the image formed by the lens. Let \( l_1, l_2 \) and \( l_3 \) denote the optical path lengths of the three rays 1, 2 and 3, respectively. Identify the correct statement.