Ray Optics

36 JEE Main questions · Physics

Refraction

PhysicsJEE Main 21 Jan 2026, Shift 1·Q21·Numerical·Moderate
Open
A collimated beam of light of diameter 2 mm is propagating along x-axis. The beam is required to be expanded in a collimated beam of diameter 14 mm using a system of two convex lenses. If first lens has focal length 40 mm, then the focal length of second lens is mm.
PhysicsJEE Main 21 Jan 2026, Shift 2·Q20·MCQ·Moderate
Open
As shown in the diagram, when the incident ray is parallel to base of the prism, the emergent ray grazes along the second surface.
If refractive index of the material of prism is $\sqrt2$ , the angle $\theta$ of prism is.
1. (1) $60^\circ$
2. (2) $75^\circ$
3. (3) $90^\circ$
4. (4) $45^\circ$
PhysicsJEE Main 22 Jan 2026, Shift 1·Q14·MCQ·Moderate
Open
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 convex lens and object undisturbed a gap of 1 cm is introduced between the lenses by moving the concave lens away, which lead to a change in magnification of total lens system to $m_2$ . The value of $\left|\dfrac{m_1}{m_2}\right|$ is .
1. (1) $\dfrac59$
2. (2) $\dfrac{5}{27}$
3. (3) $\dfrac32$
4. (4) $\dfrac{25}{27}$
Flawed question. No option is correct as printed ( $|m_1/m_2| = 5/6$ ) and no single evident misprint leads to one of the options; dropped in the source key. It is shown for completeness and is left out of practice tests.
PhysicsJEE Main 22 Jan 2026, Shift 1·Q15·MCQ·Easy–moderate
Open
Consider an equilateral prism (refractive index $\sqrt2$ ). A ray of light is incident on its one surface at a certain angle $i$ . If the emergent ray is found to graze along the other surface then the angle of refraction at the incident surface is close to .
1. (1) $15^\circ$
2. (2) $20^\circ$
3. (3) $40^\circ$
4. (4) $30^\circ$
PhysicsJEE Main 22 Jan 2026, Shift 1·Q23·Numerical·Easy–moderate
Open
A parallel beam of light travelling in air (refractive index 1.0) is incident on a convex spherical glass surface of radius of curvature 50 cm. Refractive index of glass is 1.5. The rays converge to a point at a distance x cm from the centre of the curvature of the spherical surface. The value of x is cm.
PhysicsJEE Main 22 Jan 2026, Shift 2·Q12·MCQ·Easy–moderate
Open
The wavelength of light, while it is passing through water is 540 nm. The refractive index of water is $\dfrac43$ . The wavelength of the same light when it is passing through a transparent medium having refractive index of $\dfrac32$ is nm.
1. (1)380
2. (2)840
3. (3)480
4. (4)540
PhysicsJEE Main 23 Jan 2026, Shift 1·Q1·MCQ·Easy–moderate
Open
A thin prism with angle $5^\circ$ 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 .
1. (1) $4.5^\circ$
2. (2) $6^\circ$
3. (3) $4^\circ$
4. (4) $5^\circ$
PhysicsJEE Main 23 Jan 2026, Shift 1·Q11·MCQ·Easy–moderate
Open
Consider light travelling from a medium A to medium B separated by a plane interface. If the light undergoes total internal reflection during its travel from medium A to B and the speed of light in media A and B are $2.4\times10^{8}$ m/s and $2.7\times10^{8}$ m/s respectively, then the value of critical angle is:
1. (1) $\cot^{-1}\left(\dfrac{3}{\sqrt{13}}\right)$
2. (2) $\sin^{-1}\left(\dfrac98\right)$
3. (3) $\tan^{-1}\left(\dfrac{8}{\sqrt{17}}\right)$
4. (4) $\cos^{-1}\left(\dfrac89\right)$
PhysicsJEE Main 23 Jan 2026, Shift 2·Q15·MCQ·Moderate
Open
A prism of angle $75^\circ$ and refractive index $\sqrt3$ is coated with thin film of refractive index 1.5 only at the back exit surface. To have total internal reflection at the back exit surface the incident angle must be .
( $\sin15^\circ = 0.25$ and $\sin25^\circ = 0.43$ )
1. (1)between $15^\circ$ and $20^\circ$
2. (2) $15^\circ$
3. (3) $> 25^\circ$
4. (4) $< 15^\circ$
PhysicsJEE Main 23 Jan 2026, Shift 2·Q22·Numerical·Moderate
Open
The sizes of the images of an object, formed by a thin lens are equal when the object is placed at two different positions 8 cm and 24 cm from the lens. The focal length of the lens is cm.
We corrected a printing error in the original paper
Source printed “The size of the images … are equal”.
PhysicsJEE Main 24 Jan 2026, Shift 1·Q6·MCQ·Moderate
Open
The exit surface of a prism with refractive index $n$ is coated with a material having refractive index $\dfrac{n}{2}$ . When this prism is set for minimum angle of deviation it exactly meets the condition of critical angle. The prism angle is
1. (1) $60^\circ$
2. (2) $15^\circ$
3. (3) $30^\circ$
4. (4) $45^\circ$
PhysicsJEE Main 24 Jan 2026, Shift 2·Q3·MCQ·Easy–moderate
Open
Five persons $P_1$ , $P_2$ , $P_3$ , $P_4$ and $P_5$ recorded object distance ( $u$ ) and image distance ( $v$ ) using same convex lens having power $+5$ D as (25, 96), (30, 62), (35, 37), (45, 35) and (50, 32) respectively. Identify correct statement
1. (1)Readings recorded by all persons are correct
2. (2)Reading recorded by $P_3$ persons are incorrect
3. (3)Reading recorded by $P_3$ and $P_2$ persons are incorrect
4. (4)Reading recorded by $P_4$ and $P_5$ persons are incorrect
PhysicsJEE Main 28 Jan 2026, Shift 1·Q11·MCQ·Moderate
Open
The magnitudes of power of a biconvex lens (refractive index 1.5) and that of a plano-concave lens (refractive index $= 1.7$ ) are same. If the curvature of plano-concave lens exactly matches with the curvature of back surface of the biconvex lens, then ratio of radius of curvature of front and back surface of the biconvex lens is .
1. (1) $5:2$
2. (2) $5:12$
3. (3) $12:5$
4. (4) $2:5$
PhysicsJEE Main 28 Jan 2026, Shift 1·Q24·Numerical·Easy–moderate
Open
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 $\alpha\times f$ . The value of $\alpha$ is .
(refractive index of water $= 4/3$ )
PhysicsJEE Main 28 Jan 2026, Shift 2·Q3·MCQ·Moderate
Open
A biconvex lens is formed by using two thin planoconvex lenses, as shown in the figure. The refractive index and radius of curved surfaces are also mentioned in figure. When an object is placed on the left side of lens at a distance of 30 cm from the biconvex lens, the magnification of the image will be:
1. (1) $-2$
2. (2) $+2$
3. (3) $+2.5$
4. (4) $-2.5$
PhysicsJEE Main 28 Jan 2026, Shift 2·Q18·MCQ·Moderate
Open
For a transparent prism, if the angle of minimum deviation is equal to its refracting angle, the refractive index $n$ of the prism satisfies.
1. (1) $\sqrt2 < n < 2\sqrt2$
2. (2) $1 < n < 2$
3. (3) $n \ge 2$
4. (4) $\sqrt2 < n < 2$
PhysicsJEE Main 2 Apr 2026, Shift 1·Q15·MCQ·Easy–moderate
Open
For a thin symmetric prism made of glass (refractive index 1.5), the ratio of incident angle and minimum deviation will be .
1. (1)3 : 4
2. (2)3 : 2
3. (3)2 : 1
4. (4)1 : 2
PhysicsJEE Main 2 Apr 2026, Shift 1·Q16·MCQ·Moderate
Open
Refer the figure given below. $\mu_1$ and $\mu_2$ are refractive indices of air and lens material. The height of image will be cm.
1. (1)1
2. (2)0.5
3. (3)1.2
4. (4)0.25
PhysicsJEE Main 2 Apr 2026, Shift 2·Q16·MCQ·Easy–moderate
Open
One side of an equilateral prism is painted by a transparent material of refractive index $n_2$ . The refractive index of prism is 1.6. The maximum value of $n_2$ required for total internal reflection from painted face is .
1. (1) $\dfrac{3\sqrt3}{1.6}$
2. (2) $\sqrt3$
3. (3) $\dfrac{3.2}{\sqrt3}$
4. (4) $\dfrac{4\sqrt3}{5}$
We corrected a printing error in the original paper
Source printed “minimum value of $n_2$ ”; corrected to the intended “maximum value of $n_2$ ” (TIR at the painted face needs $n_2 \le 1.6\sin60^\circ$ ).
PhysicsJEE Main 2 Apr 2026, Shift 2·Q24·Numerical·Easy–moderate
Open
If sunlight is focused on a paper using convex lens (take the lens to be equiconvex), it starts burning the paper in shortest time when the lens is kept at 30 cm above the paper. If the radius of curvature of the lens is 60 cm then the refractive index of the lens material is $\dfrac{\alpha}{10}$ . The value of $\alpha$ is .
We corrected a printing error in the original paper
Assumption “(take the lens to be equiconvex)” added; the source leaves the lens shape unstated (a plano-convex lens would give $\alpha = 30$ ).
PhysicsJEE Main 4 Apr 2026, Shift 2·Q16·MCQ·Easy–moderate
Open
A convex lens is made from glass material having refractive index of 1.4 with same radius of curvature on both sides. The ratio of its focal length and radius of curvature is .
1. (1)0.5
2. (2)2.5
3. (3)0.8
4. (4)1.25
PhysicsJEE Main 5 Apr 2026, Shift 1·Q15·MCQ·Easy–moderate
Open
A ray of light passing through an equilateral prism is having velocity $2.12\times10^{8}$ m/s in the prism material, then the minimum angle of deviation is degrees.
1. (1)45
2. (2)30
3. (3)28
4. (4)58
PhysicsJEE Main 5 Apr 2026, Shift 1·Q17·MCQ·Moderate
Open
A compound microscope is designed with two symmetric biconvex lenses. The objective lens is cut vertically, creating two identical plano-convex lenses. One of them is used in place of original objective lens. To retain same magnification keeping the object distance unchanged, the tube length has to be :-
1. (1)increased two times
2. (2)increased $\dfrac{3}{2}$ times
3. (3)decreased two times
4. (4)decreased $\dfrac{3}{2}$ times
PhysicsJEE Main 5 Apr 2026, Shift 2·Q15·MCQ·Easy–moderate
Open
A thin convex lens and a thin concave lens are kept in contact and are co-axial. Which of the following statements is correct for this combination of two lenses?
1. (1)behaves as concave lens if $|f_{\text{convex}}| > |f_{\text{concave}}|$
2. (2)behaves as concave lens if $|f_{\text{convex}}| < |f_{\text{concave}}|$
3. (3)behaves as convex lens if $|f_{\text{convex}}| > |f_{\text{concave}}|$
4. (4)Focal length of the lens system will change if the positions of two lenses are interchanged
We corrected a printing error in the original paper
Source printed “if the position of two lenses are interchanged”.
PhysicsJEE Main 5 Apr 2026, Shift 2·Q16·MCQ·Moderate
Open
An object AB is placed 15 cm on the left of a convex lens P of focal length 10 cm. Another convex lens Q is now placed 15 cm right of lens P. If the focal length of lens Q is 15 cm, the final image is
1. (1)virtual, formed at 7.5 cm right of lens Q, with a size bigger than that of AB
2. (2)real, formed at 7.5 cm right of lens Q, with a size same as that of AB
3. (3)formed at infinity.
4. (4)real, formed at 7 cm right of lens Q, with a size smaller than that of AB
We corrected a printing error in the original paper
Source printed option (2) “with a size same than that of AB”.
PhysicsJEE Main 6 Apr 2026, Shift 1·Q16·MCQ·Easy–moderate
Open
A spherical interface lens of radius R separates two media of refractive indices 1 and 1.4 respectively as shown in the figure below. A point source is placed at a distance of 4R in front of spherical interface. The magnitude of the magnification of point source image is .
1. (1)1.66
2. (2)2.33
3. (3)2.66
4. (4)1.33
PhysicsJEE Main 6 Apr 2026, Shift 2·Q17·MCQ·Easy–moderate
Open
Angle of minimum deviation is equal to the half of the angle of prism in an equilateral prism. The refractive index of the prism is .
1. (1)1.5
2. (2) $\sqrt3$
3. (3) $\sqrt2$
4. (4)1.65
We corrected a printing error in the original paper
Source printed “angle of prism is an equilateral prism”; “refreactive”.
PhysicsJEE Main 8 Apr 2026, Shift 2·Q5·MCQ·Moderate
Open
A thin biconvex lens is prepared from the glass ( $\mu = 1.5$ ) both curved surfaces of which have equal radii of 20 cm each. Left side surface of the lens is silvered from outside to make it reflecting. To have the position of image and object at the same place, the object should be placed, from the lens at a distance of cm.
1. (1)10
2. (2)12.5
3. (3)13
4. (4)13.5
PhysicsJEE Main 8 Apr 2026, Shift 2·Q17·MCQ·Moderate
Open
Light ray incident along a vector $\overrightarrow{AO}\left(\overrightarrow{AO} = 2\hat i - 3\hat j\right)$ emerges out along vector $\overrightarrow{OB}\left(\overrightarrow{OB} = C\hat i - 4\hat j\right)$ as shown in the figure below. The value of $C$ is .
1. (1)1.6
2. (2)0.16
3. (3)11.6
4. (4)16

Reflection

PhysicsJEE Main 22 Jan 2026, Shift 2·Q6·MCQ·Easy
Open
In parallax method for the determination of focal length of a concave mirror, the object should always be placed :
1. (1)between the focus (F) and the centre of curvature (C) of the mirror ONLY
2. (2)at any point beyond the focus (F) of the mirror
3. (3)beyond the centre of the curvature (C) of the mirror ONLY
4. (4)between the pole (P) and the focus (F) of the concave mirror ONLY
PhysicsJEE Main 24 Jan 2026, Shift 2·Q20·MCQ·Easy–moderate
Open
Distance between an object and three times magnified real image is 40 cm. The focal length of the mirror used is cm.
1. (1) $-15/2$
2. (2) $-10$
3. (3) $-20$
4. (4) $-15$
PhysicsJEE Main 4 Apr 2026, Shift 1·Q14·MCQ·Easy–moderate
Open
A rod of length 10 cm lies along the principal axis of a concave mirror of focal length 10 cm as shown in figure. The length of the image is cm.
1. (1)2.5
2. (2)5
3. (3)7.5
4. (4)7
We corrected a printing error in the original paper
Source printed “principle axis”.
PhysicsJEE Main 6 Apr 2026, Shift 2·Q25·Numerical·Easy–moderate
Open
A concave mirror of focal length 10 cm forms an image which is double the size of object when the object is placed at two different positions. The distance between the two positions of the object is cm.
We corrected a printing error in the original paper
Source printed “froms an image”.

Optical instruments

PhysicsJEE Main 21 Jan 2026, Shift 1·Q25·Numerical·Easy–moderate
Open
In a microscope the objective is having focal length $f_0 = 2$ cm and eye-piece is having focal length $f_e = 4$ cm. The tube length is 32 cm. The magnification produced by this microscope for normal adjustment is .
PhysicsJEE Main 24 Jan 2026, Shift 1·Q8·MCQ·Easy–moderate
Open
In a microscope of tube length 10 cm two convex lenses are arranged with focal length of 2 cm and 5 cm. Total magnification obtained with this system for normal adjustment is $(5)^{k}$ . The value of $k$ is
1. (1)2
2. (2)5
3. (3)3.5
4. (4)4
PhysicsJEE Main 4 Apr 2026, Shift 1·Q19·MCQ·Easy–moderate
Open
A telescope with objective diameter $R$ is used to observe a distant star emitting light of wavelength 500 nm, at a resolution of $5\times10^{-7}$ radian. The value of $R$ is cm.
1. (1)61
2. (2)122
3. (3)244
4. (4)305