List of top Physics Questions on Ray optics and optical instruments asked in JEE Main

One plano-convex and one plano-concave lens of same radius of curvature $'R'$ but of different materials are joined side by side as shown in the figure. If the refractive index of the material of $1$ is $\mu_1$ and that of $2$ is $\mu_2$, then the focal length of the combination is :

The eye can be regarded as a single refracting surface . The radius of curvature of this surface is equal to that of cornea ($7.8\, mm$ ). This surface separates two media of refractive indices 1 and $1.34$. Calculate the distance from the refracting surface at which a parallel beam of light will come to focus.

A concave mirror has radius of curvature of $40\, cm$. It is at the bottom of a glass that has water filled up to $5\, cm$ (see figure). If a small particle is floating on the surface of water, its image as seen, from directly above the glass, is at a distance d from the surface of water. The value of d is close to : (Refractive index of water $= 1.33$)

A convex lens is put $10 \,cm$ from a light source and it makes a sharp image on a screen, kept $10\, cm$ from the lens. Now a glass block (refractive index $1.5$) of $1.5\, cm$ thickness is placed in contact with the light source. To get the sharp image again, the screen is shifted by a distance $d$. Then $d$ is :

A convex lens (of focal length $20\, cm$) and a concave mirror, having their principal axes along the same lines, are kept $80 \,cm$ apart from each other. The concave mirror is to the right of the convex lens. When an object is kept at a distance of $30\, cm$ to the left of the convex lens, its image remains at the same position even if the concave mirror is removed. The maximum distance of the object for which this concave mirror, by itself would produce a virtual image would be :

The graph shows how the magnification $m$ produced by a thin lens varies with image distance $v$. What is the focal length of the lens used ?

A convergent doublet of separated lenses, corrected for spherical aberration, has resultant focal length of $10 \,cm$. The separation between the two lenses is $2 \,cm$. The focal lengths of the component lenses are :

In an experiment a convex lens of focal length $15\, cm$ is placed coaxially on an optical bench in front of a convex mirror at a distance of $5 \,cm$ from it. It is found that an object and its image coincide, if the object is placed at a distance of $20 \,cm $ from the lens. The focal length of the convex mirror is :

A diverging lens with magnitude of focal length $25\, cm$ is placed at a distance of $15\, cm$ from a converging lens of magnitude of focal length $20\, cm$. A beam of parallel light falls on the diverging lens. The final image formed is :

An observer looks at a distant tree of height $10\, m$ with a telescope of magnifying power of $20$. To the observer the tree appears :

In an experiment for determination of refractive index of glass of a prism by $i - \delta $ , plot, it was found that a ray incident at angle $35^{\circ}$, suffers a deviation of $40^{\circ}$ and that it emerges at angle $79^{\circ}$. ?n that case which of the following is closest to the maximum possible value of the refractive index ?

To find the focal length of a convex mirror, a student records the following data : The focal length of the convex lens is $f_1$ and that of mirror is $f_2$. Then taking index correction to be negligibly small, $f_1$ and $f_2$ are close to :

A thin convex lens of focal length ' $f'$ is put on a plane mirror as shown in the figure. When an object is kept at a distance ' $a$ ' from the lens-mirror combination, its image is formed at a distance $\frac{a}{3}$ in front of the combination. The value of ' $a$ ' is

You are asked to design a shaving mirror assuming that a person keeps it $10\,cm$ from his face and views the magnified image of the face at the closest comfortable distance of $25\, cm$. The radius of curvature of the mirror would then be :

Monochromatic light is incident on a glass prism of angle $A$. If the refractive index of the material of the prism is $u$, a ray incident at an angle $\theta$, on the face $AB$ would get transmitted through the face $AC$ of the prism provided

A thin convex lens made from crown glass $\left(\mu=\frac{3}{2}\right)$ has focal length $f$. When it is measured in two different liquids having refractive indices $\frac{4}{3}$ and $\frac{5}{3}$, it has the focal lengths $f_{1}$ and $f_{2}$ respectively. The correct relation between the focal lengths is

An object is located in a fixed position in front of a screen. Sharp image is obtained on the screen for two positions of a thin lens separated by $10\, cm$. The size of the images in two situations are in the ratio 3 : 2. What is the distance between the screen and the object ?

A printed page is pressed by a glass of water. The refractive index of the glass and water is $1.5$ and $1.33$ , respectively. If the thickness of the bottom of glass is $1 \,cm$ and depth of water is $5 \,cm$ , how much the page will appear to be shifted if viewed from the top ?

Light is incident from a medium into air at two possible angles of incidence $(A) 20^{\circ}$ and $(B) 40^{\circ}$. In the medium light travels $3.0 \,cm$ in $0.2\, ns$. The ray will :

Diameter of a plano-convex lens is $6 \,cm$ and thickness at the centre is 3 mm. If speed of light in material of lens is $2 \times 10^8$ m/s, the focal length of the lens is

A light ray falls on a square glass slab as shown in the diagram. The index of refraction of the glass, if total internal reflection is to occur at the vertical face, is equal to :

Critical angle for a pair of medium is given to be 45°. Find the ratio of the refractive index of rarer to denser medium.

A convex lens has a focal length of f = 20 cm, R1 = 15 cm, R2 = 30 cm. The refractive index of the lens is \(\frac{x}{2}\) The value of x is _______ .

A point source of light is placed at focus of convex lens, then what is the shape of wave front after passing through the lens?