List of top Physics Questions

A simple harmonic oscillator of angular frequency $2 \,rad \,s^{-1}$ is acted upon by an external force $F= \sin\, t \,N$. If the oscillator is at rest in its equilibrium position at $t\, =\, 0$, its position at later times is proportional to :
A projectile is thrown in upward direction making an angle of 60° with the horizontal direction with a velocity of 150 ms\(^{-1}\). Then, the time after which its inclination with horizontal is 45°, is
When a copper sphere is heated, percentage change is
In Young's double slit experiment, fringes of width \(\beta\) are produced on the screen kept at a distance of 1 m from the slit. When the screen is moved away by \(5 \times 10^{-2}\) m, fringe width changes by \(3 \times 10^{-5}\) m. The separation between the slits is \(1 \times 10^{-3}\) m. The wavelength of light used is .................... nm.
A uniform rod of length 2 m, specific gravity 0.5 and mass 2 kg is hinged at one end to the bottom of a tank of water (specific gravity = 1.0) filled upto a height of 1 m as shown in the figure. Taking the case \(\theta \neq 0°\), the force exerted by the hinge on the rod is
Find the frequency of light which ejects electrons from a metal surface fully stopped by a retarding potential of 3 V. The photoelectric effect begins in this metal at a frequency of \(6 \times 10^{15}\) Hz.
Out of a photon and an electron, the equation \(E = Pc\), is valid for
Equations of a stationary and a travelling waves are as follows: \(y_1 = a\sin kx\cos\omega t\) and \(y_2 = a\sin(\omega t - kx)\). The phase difference between two points \(x_1 = \dfrac{\pi}{3k}\) and \(x_2 = \dfrac{3\pi}{2k}\) are \(\phi_1\) and \(\phi_2\) respectively for two waves. The ratio \(\dfrac{\phi_1}{\phi_2}\) is
A small block of wood of specific gravity 0.5 is submerged at a depth of 1.2 m in a vessel filled with water. The vessel is accelerated upwards with an acceleration \(a_0 = g/2\). Time taken by the block to reach the surface, if it is released with zero initial velocity is
An electron beam accelerated from rest through a potential difference of 5000 V in vacuum is allowed to impinge on a surface normally. The incident current is 50 \(\mu\)A and if the electron comes to rest on striking the surface, the force on it is
Figure shows an irregular block of material of refractive index \(\sqrt{2}\). A ray of light strikes the face AB as shown in figure. After refraction, it is incident on a spherical surface CD of radius of curvature 0.4 m and enters a medium of refractive index 1.514 to meet PQ at E. Find the distance OE upto two places of decimal.
The frequency of sonometer wire is \(f\), but when the weights producing the tensions are completely immersed in water, the frequency becomes \(f/2\) and on immersing the weights in a certain liquid, the frequency becomes \(f/3\). The specific gravity of the liquid is
The ratio of the energy required to raise a satellite upto a height \(h\) above the earth to the kinetic energy of the satellite into the orbit is
In the circuit diagram shown (15 V supply, \(R_1 = 500\,\Omega\), series resistance \(1500\,\Omega\), Zener voltage \(V_z = 10\) V), the current through the Zener diode is
Two unequal masses are connected on two sides of a light string passing over a light and smooth pulley as shown in the figure. The system is released from the rest. The larger mass is stopped for a moment, 1 s after the system is set into motion. The time elapsed before the string is tight again is
A large slab of mass 5 kg lies on a smooth horizontal surface, with a block of mass 4 kg lying on the top of it; the coefficient of friction between the block and the slab is 0.25. If the block is pulled horizontally by a force of \(F = 6\) N, the work done by the force of friction on the slab between the instants \(t = 2\) s and \(t = 3\) s is
A small particle of mass \(m\) is released from rest from point A inside a smooth hemispherical bowl as shown in the figure. The ratio \(x\) of magnitude of centripetal force and normal reaction on the particle at any point B varies with \(\theta\) as
A solid cylinder is rolling down on an inclined plane of angle \(\theta\). The coefficient of static friction between the plane and the cylinder is \(\mu_s\). The condition for the cylinder not to slip is
For a given density of a planet, the orbital speed of satellite near the surface of the planet of radius \(R\) is proportional to
A block of mass \(m\) is lying on the edge having inclination angle \(\alpha = \tan^{-1}\!\!\left(\dfrac{1}{5}\right)\). Wedge is moving with a constant acceleration \(a = 2\) ms\(^{-2}\). The minimum value of coefficient of friction \(\mu\), so that \(m\) remains stationary with respect to wedge is
Order of magnitude of density of uranium nucleus is \((m_p = 1.6 \times 10^{-27}\) kg\()\)
Two point masses 1 and 2 move with uniform velocities \(\mathbf{v}_1\) and \(\mathbf{v}_2\) respectively. Their initial position vectors are \(\mathbf{r}_1\) and \(\mathbf{r}_2\), respectively. Which of the following should be satisfied for the collision of the point masses?
The specific heat at constant volume for the monoatomic argon is 0.075 kcal/kg-K, whereas its gram molecular specific heat is \(C_V = 2.98\) cal/mol K. The mass of the argon atom is
Two identical coherent sources placed on a diameter of a circle of radius \(R\) at separation \(x\) \((x \ll R)\) symmetrically about the centre of the circle. The sources emit identical wavelength \(\lambda\) each. The number of points on the circle with maximum intensity is \((x = 5\lambda)\)
A neutron moving with a speed \(v\) makes a head on collision with a hydrogen atom in ground state kept at rest. The minimum kinetic energy of neutron for which inelastic collision will take place is