List of top Questions asked in JEE Main

A ray parallel to the x-axis (principal axis of curved surface) is incident. The x-coordinate where the ray cuts the x-axis is: (The radius of curvature is 50 cm and $ \mu = 1.5 $).

Combination of lenses are arranged in case I and case II as shown in the figure. In case I, $ f_1 = 5 \, \text{cm} $, and in case II, $ f_2 = 4 \, \text{cm} $, the object is at $ -10 \, \text{cm} $. Magnification in two cases are $ m_1 $ and $ m_2 $. Find $ \left| \frac{m_1}{m_2} \right| $.

Focal length of objective lens and eyepiece lens are 1.25 cm and 5 cm and tube length is 26 cm. Find magnification of compound microscope in normal adjustment.

Find the angle $A$ of the second prism so that the light ray suffers dispersion without deviation:

Two media of refractive indices $n_1$ and $n_2$ have a plane interface. In the first medium, speed of light is $2.4\times10^8$ m/s and in the second medium, it is $2.8\times10^8$ m/s. Find the critical angle when light travels from 1st medium to 2nd medium:

When an object is kept at distance 8 cm and 24 cm from a convex lens, magnitude of magnification is same in both cases. Find focal length (in cm) of the lens :

A prism with angle of prism 75° and having refractive index $\sqrt{3}$ has a slab of refractive index 1.5 kept on one side of the prism as shown. Find angle of incidence such that TIR occurs at slab prism interface. (Given sin 15° = 0.25 and sin 25° = 0.43) :

Light is incident at such an angle so that minimum deviation takes place. Now a film of refractive index RI = $n/2$ is stick on other face such that total internal reflection takes place on second surface. Find angle of prism :

Power of convex lens is $5$ D. Four students measure object and image distances as shown.

Focal length of a convex lens in air is f = 18 cm. It is immersed in a liquid of refractive index 4/3. If change in focal length of lens is $\Delta f$ = nf, Find n. [Given refractive index of lens is 1.5] :

The minimum deviation produced by a prism is equal to the refracting angle of prism, then choose the range of refractive index ($\mu$) of material of prism:

Find magnification due to lens:

Given: \[ R_1 = 15\,\text{cm}, \quad R_2 = 12\,\text{cm}, \quad \text{Object distance } = 30\,\text{cm} \]

Two rods of equal length $60\,\text{cm}$ each are joined together end to end. The coefficients of linear expansion of the rods are $24\times10^{-6}\^{\circ}\text{C}^{-1}$ and $1.2\times10^{-5}\^{\circ}\text{C}^{-1}$. Their initial temperature is $30^{\circ}\text{C}$, which is increased to $100^{\circ}\text{C}$. Find the final length of the combination (in cm).

Find the change in internal energy of a gas if its temperature changes by $10\,\text{K}$. Number of moles of gas is $10$, $C_p$ (specific heat at constant pressure) is $7\,\text{cal\,K}^{-1}\text{mol}^{-1}$ and $R$ (gas constant) $= 2\,\text{cal\,K}^{-1}\text{mol}^{-1}$.

Find change in internal energy of gas if its temperature changes by $10$ K. Number of moles of gas is $10$. $C_p$ (specific heat at constant pressure) of the gas is $7$ cal/K-mol and $R$ (gas constant) is $2$ cal/K.

As shown in the figure, six rods of same geometry are connected and maintained at temperatures $100^\circ\text{C}$ and $40^\circ\text{C}$. The temperature at points $A$ and $B$ are:

For an ideal gas in a reversible process ($\Delta Q = 0$), volume becomes $8$ times and temperature becomes $\dfrac{1}{4}$ times the initial value. Identify the gas:

For the following change, \[ \mathrm{H_2O(l)} \xrightarrow[100^\circ C]{5^\circ C} \mathrm{H_2O(g)} \] Select the correct answer:

Work done in an isobaric process is 100 Joules. If adiabatic constant for the gas is 1.4, find the heat given to the gas.

In an adiabatic process, the temperature reduces to $ \frac{1}{4} $th and volume increases to 8 times. Find the adiabatic constant of the gas.

Match the column with the correct numerical values of energy/heat in column-II (R is universal gas constant)

Find the change in internal energy of gas if its temperature changes by 10K. Number of moles of gas is 10, $ C_P $ (specific heat at constant pressure of the gas) is 7 cal/K-mol and $ R $ (gas constant) = 2 cal/K.

Two balls made of the same material collide perfectly inelastically as shown. The energy lost in the collision is completely utilized in raising the temperature of each ball. Find the rise in temperature of the balls. (Specific heat $=31$ cal/kg-$^\circ$C):

Hydrogen and oxygen gases have the same RMS speed. If hydrogen gas is at $27^\circ\mathrm{C}$, find the temperature of oxygen gas.

An air bubble inside water at depth h = 5 m rises to surface. At bottom temperature is $T_1 = 17^\circ C$ and volume is $V_1 = 2.9 \text{ cm}^3$. At the surface the temperature is $T_2 = 27^\circ C$. Find final volume (Given that number of moles remains same and $P_0 = 10^5$ Pa, and g=10 m/s$^2$):