Physics Optics questions from NEET UG 2023.
The phenomenon of total internal reflection occurs when light travels from
In the figure shown here, what is the equivalent focal length of the combination of lenses (Assume that all layers are thin)? 
A lens is made up of 3 different transparent media as shown in figure. A point object $O$ is placed on its axis beyond $2 f$. How many real images will be obtained on the other side? 
Light travels a distance$x$in time${t}_{1}$ in air and $10x$ in time ${t}_{2}$ in another denser medium. What is the critical angle for this medium?
$\varepsilon_0$ and $\mu_0$ are the electric permittivity and magnetic permeability of free space respectively. If the corresponding quantities of a medium are $2 \varepsilon_0$ and $1.5 \mu_0$ respectively, the refractive index of the medium will nearly be
Two thin lenses are of same focal lengths $f$, but one is convex and the other one is concave. When they are placed in contact with each other, the equivalent focal length of the combination will be:
 Which set of colours will come out in air for a situation shown in figure?
An object is mounted on a wall. Its image of equal size is to be obtained on a parallel wall with the help of a convex lens placed between these walls. The lens is kept at distance $x$ in front of the second wall. The required focal length of the lens will be
For Young's double slit experiment, two statements are given below: Statement $I$: If screen is moved away from the plane of slits, angular separation of the fringes remains constant. Statement $II$: If the monochromatic source is replaced by another monochromatic source of larger wavelength, the angular separation of fringes decreases. In the light of the above statements, choose the correct answer from the options given below:
A horizontal ray of light is incident on the right-angled prism with prism angle $6^{\circ}$. If the refractive index of the material of the prism is 1.5 , then the angle of emergence will be 