List of top Physics Questions

A square loop of side \(a\) carries current \(i\). Find magnetic field at centre.
A short bar magnet is placed with its south pole towards geographical north. Neutral points are at 20 cm from centre. Given \(B_H = 0.3\times10^{-4}\,Wb/m^2\), find magnetic moment.
A magnet makes 40 oscillations per minute at a place with \(B_H = 0.1\times10^{-5}T\). At another place, time period is 2.5 s. Find \(B_H\) there.
Coercivity \(=4\times10^3 A/m\). Solenoid: 500 turns, length 1 m. Find current needed to demagnetise.
Fraction decayed in 6 days is \(7/8\). Find fraction decayed in 10 days.
Nucleus emits \(\alpha\)-particle. Find recoil speed of daughter nucleus.
When \({}^{228}_{90}Th\) transforms to \({}^{212}_{83}Bi\), find number of \(\alpha\) and \(\beta\) particles emitted.
Work done in increasing capacitor voltage from 5V to 10V is \(W\). Find work from 0V to 5V.
In the circuit shown, find voltmeter reading.
For a real gas, variation of \(\frac{pV}{RT}\) with pressure \(p\) is shown. Identify correct curve.
Liquid is filled in a flask. On heating, what happens to liquid level?
Two rods (one semi-circular and other straight) of same material and cross-section are joined. The ratio of heat transferred through semi-circular rod to straight rod is graphics[width=0.45\linewidth]{PHYSICS/QP21.png}
Two particles execute SHM with same amplitude and frequency. When displacement is half amplitude, find phase difference.
Pressure-volume relation: jar A has \(V,T\); jar B has \(V/4,2T\). Find ratio of number of molecules.
Two identical vessels contain gases at \(T_0, P_0\). One heated to \(2T_0\). Find pressure \(P\) and number of moles \(n\).
Strain vs stress curves for wires \(P, Q, R\). Which is correct?
Several spherical drops (radius \(r\)) combine to form one drop (radius \(R\)). Find change in surface energy.
Two substances of densities \(\rho_1\) and \(\rho_2\) are mixed in equal volumes, mixture density = 4. When mixed in equal masses, density = 3. Find \(\rho_1, \rho_2\).
Four thin rods of same mass \(M\) and length \(l\) form a square. Find moment of inertia about axis through centre and perpendicular to plane.
A wheel rotates at \(20\,rad/s\) and stops in \(4s\). Find work done if \(I=0.20\,kg\,m^2\).
A particle moves along x-axis under force \(F(x) = -kx + ax^2\). Find nature of potential energy graph.
A body \(A\) rests on smooth surface. Body \(B\) placed over \(A\) has coefficient of friction \(0.5\). Find force required to just move \(B\).
The acceleration-time graph of a body is shown below. The most probable velocity-time graph of the body is
The acceleration of block \( B \) in the given pulley system is
Two seconds after projection, a projectile is travelling in a direction inclined at \(30^\circ\) to the horizontal. After one more sec, it is travelling horizontally. Find its velocity magnitude and direction.