Optics - Physics Previous Year Questions

A thin equi-convex lens is made of glass of refractive index 1.5 and its focal length is 0.2 m. If it acts as a concave lens of focal length 0.5 cm when dipped in a liquid, the refractive index of the liquid is

Two plane mirrors A and B are aligned parallel to each other as shown in the figure.

A ray of light is incident at an angle 30\(^\circ\) at a point just inside one end of A. The plane of incidence coincides with the plane of the figure. The maximum number of times, the ray undergoes reflection (excluding the first one) before it emerges out is

A mosquito O is sitting infront of a glass rod having spherical end of radius of curvature 40 cm. The image would be formed at

In a YDSE, the light of wavelength \(\lambda=5000\mathop A\limits^o\) is used, which emerges in phase from two slits at \(a\) distance \(d=3 \times 10^{-7} \mathrm{~m}\) apart. A transparent sheet of thickness \(t=1.5 \times 10^{-7} \mathrm{~m}\) and refractive index \(\mu=1.25\) is placed over one of the slits. What is the new angular position of the central maxima of the interference pattern, from the centre of the screen? Find the value of \(y\).

In a Young's double slit experiment for a particular wavelength of light the distance between third dark and fifth bright fringe is 1.63 mm . If the distance between two slit is 1 mm and distance between slit and screen is 1 metre. Then, the wavelength of light is