List of top Physics Questions on Optics asked in JEE Main

Object is placed at $40 \text{ cm}$ from spherical surface whose radius of curvature is $20 \text{ cm}$. Find height of image formed.

A convex lens of refractive index $1.5$ and focal length $f=18$ cm is immersed in water. The difference in focal lengths of the given lens when it is in water and in air is $ \alpha \times f $. Find the value of $ \alpha $. (Given: refractive index of water $=\dfrac{4}{3}$)

Angular momentum of the electron in a hydrogen atom is $\frac{3h}{2\pi}$, then find the energy of the electron in the orbit :-

Thin symmetric prism of $\mu = 1.5$. Find ratio of incident angle and minimum deviation.

Given below are two statements: Statement I: A plane wave after passing through a prism remains a plane wave, but passing through a small pin hole may become a spherical wave. Statement II: The curvature of a spherical wave emerging from a slit will increase for increasing slit width. In the light of the above statements, choose the correct answer:

The magnitudes of power of a biconvex lens (refractive index $1.5$) and that of a plano-convex lens (refractive index $1.7$) are same. If the curvature of the plano-convex lens exactly matches with the curvature of the back surface of the biconvex lens, then the ratio of radii of curvature of the front and back surfaces of the biconvex lens is:

The strain-stress plot for materials A, B, C and D is shown in the figure. Which material has the largest Young's modulus?

A thin convex lens of focal length $ 5 $ cm and a thin concave lens of focal length $ 4 $ cm are combined together (without any gap), and this combination has magnification $ m_1 $ when an object is placed $ 10 $ cm before the convex lens.

Keeping the positions of the convex lens and the object undisturbed, a gap of $ 1 $ cm is introduced between the lenses by moving the concave lens away. This leads to a change in magnification of the total lens system to $ m_2 $.

The value of $ \dfrac{m_1}{m_2} $ is

A thin prism with angle 5° of refractive index 1.72 is combined with another prism of refractive index 1.9 to produce dispersion without deviation. The angle of second prism is :

In a screw gauge, the zero of the circular scale lies 3 divisions above the horizontal pitch line when their metallic studs are brought in contact. Using this instrument thickness of a sheet is measured. If pitch scale reading is 1 mm and the circular scale reading is 51 then the correct thickness of the sheet is_______ mm. [Assume least count is 0.01 mm]}

When an object is placed 40 cm away from a spherical mirror an image of magnification $\frac{1}{2}$ is produced. To obtain an image with magnification of $\frac{1}{3}$, the object is to be moved:

Two polarisers $ P_1 $ and $ P_2 $ are placed in such a way that the intensity of the transmitted light will be zero. A third polariser $ P_3 $ is inserted in between $ P_1 $ and $ P_2 $, at the particular angle between $ P_1 $ and $ P_2 $. The transmitted intensity of the light passing the through all three polarisers is maximum. The angle between the polarisers $ P_2 $ and $ P_3 $ is:

A monochromatic light of frequency $ 5 \times 10^{14} $ Hz travelling through air, is incident on a medium of refractive index '2'. Wavelength of the refracted light will be :

For the determination of refractive index of glass slab, a travelling microscope is used whose main scale contains 300 equal divisions equals to 15 cm. The vernier scale attached to the microscope has 25 divisions equals to 24 divisions of main scale. The least count (LC) of the travelling microscope is (in cm):

Two concave refracting surfaces of equal radii of curvature and refractive index 1.5 face each other in air as shown in figure. A point object O is placed midway, between P and B. The separation between the images of O, formed by each refracting surface is:

Two identical symmetric double convex lenses of focal length $ f $ are cut into two equal parts $ L_1, L_2 $ by the AB plane and $ L_3, L_4 $ by the XY plane as shown in the figure respectively. The ratio of focal lengths of lenses $ L_1 $ and $ L_3 $ is:

In the diagram given below, there are three lenses formed. Considering negligible thickness of each of them as compared to $ R_1 $ and $ R_2 $, i.e., the radii of curvature for upper and lower surfaces of the glass lens, the power of the combination is:

A ray of light suffers minimum deviation when incident on a prism having angle of the prism equal to $60^\circ$. The refractive index of the prism material is $ \sqrt{2} $. The angle of incidence (in degrees) is ______ .

A bi-convex lens has radius of curvature of both the surfaces same as $ \frac{1}{6} \, \text{cm} $. If this lens is required to be replaced by another convex lens having different radii of curvatures on both sides $ (R_1 \neq R_2) $, without any change in lens power then possible combination of $ R_1 $ and $ R_2 $ is:

A spherical surface separates two media of refractive indices $ n_1 = 1 $ and $ n_2 = 1.5 $ as shown in the figure. Distance of the image of an object $ O $, if $ C $ is the center of curvature of the spherical surface and $ R $ is the radius of curvature, is:

A slanted object AB is placed on one side of convex lens as shown in the diagram. The image is formed on the opposite side. Angle made by the image with principal axis is:

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R)
Assertion (A) : Refractive index of glass is higher than that of air.
Reason (R) : Optical density of a medium is directly proportionate to its mass density which results in a proportionate refractive index.
In the light of the above statements, choose the most appropriate answer from the options given below :

Light from a point source in air falls on a spherical glass surface (refractive index, $ \mu = 1.5 $ and radius of curvature $ R = 50 $ cm). The image is formed at a distance of 200 cm from the glass surface inside the glass. The magnitude of distance of the light source from the glass surface is 1cm.

Distance between object and its image (magnified by $-\frac{1}{3}$ ) is 30 cm. The focal length of the mirror used is $\left(\frac{\mathrm{x}}{4}\right) \mathrm{cm}$, where magnitude of value of x is _______ .

A small mirror of mass $m$ is suspended by a massless thread of length $l$. Then the small angle through which the thread will be deflected when a short pulse of laser of energy $E$ falls normal on the mirror ( $c=$ speed of light in vacuum and $g=$ acceleration due to gravity).