List of top Physics Questions on Ray optics and optical instruments asked in NEET (UG)

Light with an energy flux of 25 × 10⁴ Wm^-2 falls on a perfectly reflecting surface at normal incidence. If the surface area is 15 cm², the average force exerted on the surface is:

The given graph represents V – I characteristic for a semiconductor device

Which of the following statement is correct?

If the focal length of objective lens is increased then magnifying power of:

If the focal length of objective lens is increased then magnifying power of

For a normal eye, the cornea of eye provides a converging power of 40 D and the least converging power of the eye lens behind the comes is 20 D. Using this information, the distance between the retina and the comea-eye lens can be estimated to be

A plano convex lens fits exactly into a plano concave lens. Their plane surfaces are parallel to each other. If lenses are made of different materials of refractive indices $\mu_1$ and $\mu_2$ and $R$ is the radius of curvature of the curved surface of the lenses, then the focal length of combination is

For a normal eye, the cornea of eye provides a converging power of $40\, D$ and the least converging power of the eye lens behind the cornea is $20\, D$. Using this information, the distance between the retina and the cornea -eye lens can be estimated to be -

When a biconvex lens of glass having refractive index $1.47$ is dipped in a liquid, it acts as a plane sheet of glass. This implies that the liquid must have refractive index

A rod of length $10\, cm$ lies along the principal axis of a concave mirror of focal length $10\, cm$ in such a way that its end closer to the pole is $20\, cm$ away from the mirror. The length of the image is

A biconvex lens has a radius of curvature of magnitude $20\, cm$. Which one of the following options describe best the image formed of an object of height $2 \,cm$ placed $30\, cm$ from the lens?

A converging beam of rays is incident on a diverging lens. Having passed through the lens the rays intersect at a point $15\,cm$ from the lens on the opposite side. If the lens is removed the point where the rays meet will move $5\,cm$ closer to the lens. The focal length of the lens is

A thin prism of angle $15^{\circ}$ made of glass of refractive index ($ {\mu}_1 = 1.5 $ is combined with another prism of glass of refractive index $ {\mu}_2 = 1.75$. The combination of the prisms produces dispersion without deviation. The angle of the second prism should be

A lens having focal length $f$ and aperture of diameter $d$ forms an image of intensity $I$. Aperture of diameter $\frac{d}{2}$ in central region of lens is covered by a black paper. Focal length of lens and intensity of image now will be respectively

A ray of light travelling in a transparent medium of refractive index $ \mu $, falls on a surface separating the medium from air at an angle of incidence of 45$^{\circ}$. For which of the following value of $ \mu $. the ray can undergo total internal reflection?

A small coin is resting on the bottom of a beaker filled with liquid. A ray of light from the coin travels upto the surface of the liquid and moves along its surface. How fast is the light travelling in the liquid?

A convex lens and a concave lens, each having same focal length of 25 cm, are put in contact to form a combination of lenses. The power in diopters of the combination is :

A microscope is focused on a mark on a piece of paper and then a slab of glass of thickness 3 cm and refractive index 1.5 is placed over the mark. How should the microscope be moved to get the mark in focus again?

A telescope has an objective lens of 10 cm diameter and is situated at a distance of one kilometer from two objects. The minimum distance between these two objects, which can be resolved by the telescope, when the mean wavelength of light is 5000 Å, is of the order of

The refractive index of the material of a prism is 2 and its refracting angle is 30º. One of the refracting surfaces of the prism is made a mirror inwards. A beam of monochromatic light entering the prism from the other face will retrace its path after reflection form the mirrored surface if its angle of incidence on the prism is

A beam of light composed of red and green rays is incident obliquely at a point on the face of a rectangular glass slab. When coming out on the opposite parallel face, the red and green rays emerge from

A given ray of light suffers minimum deviation in an equilateral prism P. Additional prisms Q and R of identical shape and of the same material as P are now added as shown in the figure. The ray will suffer

Optical fibre are based on

A ray of light travelling in air haves wavelength λ, frequency n, velocity v and intensity I. If this ray enters into water then these parameter are λ', n' , v' and I' respectively. Which relation is correct

A disc is placed on a surface of pond which has refractive index 5/3.A source of light is placed 4 m below the surface of liquid. The minimum radius of disc will be so light is not coming out