List of top Physics Questions asked in JEE Main

If \(x\) gm of water at \(50^\circ\text{C}\) cools to \(0^\circ\text{C}\), the heat released is \(H\). If \((100 - x)\) gm of water at \(50^\circ\text{C}\) is completely vapourised, the heat required is also \(H\). Find \(x\).

Consider the nuclear reaction: \[ {}^{2}_{1}H + {}^{2}_{1}H \rightarrow {}^{4}_{2}He \] Binding energy per nucleon of \( {}^{2}_{1}H \) and \( {}^{4}_{2}He \) are \(1.1\,\text{MeV}\) and \(7\,\text{MeV}\) respectively. Find the energy released in the nuclear reaction.

Find the electric field for the given electrostatic potential field at point \(P(2,3)\): \[ V = 5(x^2 - y^2) \]

If the system shown in the figure is released from rest, find the speed of the \(6\,\text{kg}\) block just before hitting the ground. \((g = 10\,\text{m/s}^2)\)

Minimum deviation for an equilateral prism is \(30^\circ\). The refractive index of the prism material is:

If moment of inertia of rod about axis AB is equal to moment of inertia of solid sphere about an axis parallel to AB which is at 9m from AB axis as shown in the figure. If \( R = \frac{\alpha}{2} \), then find \( \alpha \).

Find the work done in expanding a soap bubble from radius \(1\,\text{cm}\) to \(2\,\text{cm}\). Surface tension is \( \gamma = 7.2 \times 10^{-2}\,\text{N/m} \).

Electric field at the centre of a semi-circular ring of radius \(10\,\text{cm}\) is \(100\,\text{V/m}\). Find the charge on the ring if the charge distribution is uniform.

An object is placed in air (\(n_1 = 1\)) at a distance \(4R\) from a spherical refracting surface that separates air from a medium of refractive index \(n_2 = 1.4\). The surface has a radius of curvature \(R\), with its centre lying in the second medium. Find the magnitude of magnification of the image formed.

In an AC series circuit supply voltage \(V_{\text{rms}} = 100\) volts; \(R = 80\,\Omega\), \(X_L = 80\,\Omega\) and source frequency is \(f = 50\) Hz. Find the power factor.

A block of mass \(m\) is released from height \(h\) on a smooth plane. If the normal force on the top of the circular part is \(3mg\), find \(h\).

Find dimensions of \( \dfrac{A}{B} \) if \[ \left( P + \frac{A^2}{B} \right) + \frac{1}{2}\rho V^2 = \text{constant}, \] where \( P \rightarrow \) pressure, \( \rho \rightarrow \) density, \( V \rightarrow \) speed.

If the right plate of a parallel plate capacitor is pulled with constant velocity as shown in the figure, find how the rate of change of energy stored in the capacitor depends on the separation \(x\).

Find the length of image of rod \(AB\). The rod is placed in front of a concave mirror of focal length \(f = 10\,\text{cm}\). End \(A\) is \(20\,\text{cm}\) from the mirror and the length \(AB = 10\,\text{cm}\).

A particle is moving along the \(x\)-axis where the speed varies as \[ v^2 = 100 - x^2 \] Determine the time period.

A solid sphere of mass \(M\) and radius \(R\) is split into two pieces of masses \( \frac{7M{8} \) and \( \frac{M}{8} \). The piece of mass \( \frac{7M}{8} \) is converted into a disc of radius \(2R\) and thickness \(t\) whose moment of inertia is \(I_1\). The other piece is made into a solid sphere with moment of inertia \(I_2\). Find \( \frac{I_1}{I_2} \).}

Length of rods are \( \ell \) and \(2\ell\) respectively and their Young's modulus are \( \gamma \) and \(2\gamma\) respectively. Given: \[ \ell = 0.314\,\text{m}, \quad R = 0.2\,\text{mm} \,(\text{same}), \quad \gamma = 2\times10^9 \]

Find the total extension \( \Delta \ell \).

Nuclei \(A\) and \(B\) form a nucleus \(C\). Binding energy per nucleon for \(A, B\) and \(C\) are \(3\,\text{MeV}, 7\,\text{MeV}\) and \(6\,\text{MeV}\) respectively. Find the energy produced in the reaction: \[ 2A^{3} + B^{4} \rightarrow C^{10} \]