JEE Main Physics — Optics previous year questions with solutions.
Visible light of wavelength $6000\times {10}^{-8}cm$ falls normally on a single slit and produces a diffraction pattern. It is found that the second diffraction minimum is at ${60}^{o}$ from the central maximum. If the first minimum is produced at ${\theta }_{1},$ then ${\theta }_{1}$ is close to
In a Young's double slit experiment,$16$ fringes are observed in a certain segment of the screen when light of wavelength $700\mathrm{nm}$ is used. If the wavelength of light is changed to $400\mathrm{nm}$, the number of fringes observed in the same segment of the screen would be :
A Young's double-slit experiment is performed using monochromatic light of wavelength $\lambda$. The intensity of light at a point on the screen, where the path difference is $\lambda$, is $K$ units. The intensity of light at a point where the path difference is $\frac{\lambda }{6}$ is given by $\frac{\mathrm{nK}}{12}$, where $n$ is an integer. The value of $n$ is
Two coherent sources of sound, ${S}_{1}$ and ${S}_{2},$ produce sound waves of the same wavelength $\lambda =1m$ are in phase. ${S}_{1}$ and ${S}_{2}$ are placed $1.5m$ apart (see fig). A listener, located at $L$, directly in front of ${S}_{2}$, finds that the intensity is at a minimum when he is $2m$ away from ${S}_{2}$. The listener moves away from ${S}_{1}$, keeping the distance from ${S}_{2}$ fixed. The adjacent maximum of intensity is observed when the listener is at a distance $d$ from ${S}_{1}$. Then $d$ is : 
A vessel of depth $2h$ is half filled with a liquid of refractive index $2\sqrt{2}$ and the upper half with another liquid of refractive index $\sqrt{2}$ . The liquids are immiscible. The apparent depth of the inner surface of the bottom of the vessel will be
In a Young’s double slit experiment, the separation between the slits is $0.15mm$ . In the experiment, a source of light of wavelength $589nm$ is used and the interference pattern is observed on a screen kept $1.5m$ away. The separation between the successive bright fringes on the screen is:
A thin lens made of glass (refractive index $=1.5$ ) of focal length $f=16cm$ is immersed in a liquid of refractive index $1.42$ . If its focal length in liquid is ${f}_{l}$ , then the ratio ${f}_{l}/f$ is closest to the integer:
Interference fringes are observed on a screen by illuminating two thin slits $1\mathrm{mm}$ apart with a light source $(\lambda =632.8\mathrm{nm})$. The distance between the screen and the slits is $100\mathrm{cm}$. If a bright fringe is observed on a screen at distance of $1.27\mathrm{mm}$ from the central bright fringe, then the path difference between the waves, which are reaching this point from the slits is close to :
A light ray enters a solid glass sphere of refractive index $\mu =\sqrt{3}$ at an angle of incidence $60^{\circ}$. The ray is both reflected and refracted at the farther surface of the sphere. The angle (in degrees) between the reflected and refracted rays at this surface is _____________.
The critical angle of a medium for a specific wavelength, if the medium has relative permittivity $3$ and relative permeability $\frac{4}{3}$ for this wavelength, will be:
Orange light of wavelength $6000\times {10}^{–10}m$ illuminates a single slit of width $0.6\times {10}^{–4}m$. The maximum possible number of diffraction minima produced on both sides of the central maximum is __________
An object is gradually moving away from the focal point of a concave mirror along the axis of the mirror. The graphical representation of the magnitude of linear magnification $(m)$ versus distance of the object from the mirror $(x)$ is correctly given by (Graphs are drawn schematically and are not to scale)
For a concave lens of focal length $f$, the relation between object and image distance $u$ and $v,$ respectively, from its pole can best be represented by ($u=v$ is the reference line):
In a Young's double slit experiment $15$ fringes are observed on a small portion of the screen when light of wavelength $500nm$ is used. Ten fringes are observed on the same section of the screen when another light source of wavelength $\lambda$ is used. Then the value of $\lambda$ is (in $nm$ ) __________.
In a compound microscope, the magnified virtual image is formed at a distance of $25\text{ cm}$ from the eye-piece. The focal length of its objective lens is $1\text{ cm}$. If the magnification is $100$ and the tube length of the microscope is $20\text{ cm}$, then the focal length of the eye-piece lens (in $\text{cm}$) is ______
A prism of angle $A=1^{\circ}$ $\mu =1.5$. A good estimate for the minimum angle of deviation (in degrees) is close to $\frac{N}{10}.$ Value of $N$ is $\ldots \ldots \ldots$
An observer can see through a small hole on the side of a jar (radius $15\mathrm{cm}$ ) at a point at height of $15\mathrm{cm}$ from the bottom (see figure). The hole is at a height of $45\mathrm{cm}$. When the jar is filled with a liquid up to a height of $30\mathrm{cm}$ the same observer can see the edge at the bottom of the jar. If the refractive index of the liquid is$\frac{N}{100},$ where $N$ is an integer, the value of $N$ is 
In Youngs double slit experiment the fringe width is β...
If we need a magnification of $375$ from a compound microscope of tube length $150mm$ and an objective of focal length $5mm,$ the focal length of the eye-piece, should be close to:
The aperture diameter of a telescope is $5m$ . The separation between the moon and the earth is $4\times {10}^{5}km$ . With light of wavelength of $5500Å$ , the minimum separation between objects on the surface of moon, so that they are just resolved, is close to:
In a Young's double slit experiment, light of $500\mathrm{nm}$ is used to produce and interference pattern. When the distance between the slits is $0.05\mathrm{mm},$ the angular width (in degree) of the fringes formed on the distance screen is close to :
A compound microscope consists of an objective lens of focal length $1\mathrm{cm}$ and an eye piece of focal length $5\mathrm{cm}$ with a separation of $10\mathrm{cm}.$ The distance between an object and the objective lens, at which the strain on the eye is minimum is $\frac{n}{40}\mathrm{cm}.$ The value of $n$ is.......
A spherical mirror is obtained as shown in the figure from a hollow glass sphere, if an object is positioned in front of the mirror, what will be the nature and magnification of the image of the object? (Figure down as schematic and not to scale) 
There is a small source of light at some depth below the surface of water (refractive index $=\frac{4}{3}$ ) in a tank of large cross sectional surface area. Neglecting any reflection from the bottom and absorption by water, percentage of light that emerges out of surface is (nearly): [Use the fact that surface area of a spherical cap of height $h$ and radius of curvature $r$ is $2\pi rh$ ]