List of top Physics Questions

At constant pressure, if equal amounts of heat are supplied to a monoatomic gas and a rigid diatomic gas, then the ratio of the changes in the internal energies of the monoatomic and diatomic gases is:

A circular disc of radius \(15\,cm\) and mass \(10\,kg\) is suspended by a wire attached to its centre. When the wire is twisted by rotating the disc and released, the period of torsional oscillations of the disc is \(1.5\,s\). The torsional spring constant of the wire is nearly:

If the excess pressure inside a spherical mercury drop is \(1240\,Nm^{-2}\), then the radius of the mercury drop is:

A body is thrown vertically upwards from the surface of the earth with a velocity \(K\) times the orbital velocity of a satellite near the surface of the earth. If the maximum height reached by the body is 200% more than the radius of the earth, then the value of \(K^{2}\) is:

If the Poisson's ratio of the material of a wire is 0.35, then the ratio of the longitudinal and volume strains of the wire is:

A tank contains 140 cm height of water at the bottom and an oil of density \(900\,kg\,m^{-3}\) to a height of 200 cm above water. If the liquids are immiscible, then the initial velocity of efflux of water through a small opening at the bottom of the tank is:

A flag on a boat at rest is fluttering in the south-east direction when the wind is blowing at a speed of \(72\) kmph. If the boat starts moving towards south with a speed of \(36\sqrt2\) kmph, then the direction of the flag on the boat is:

A tank of height \(5\,m\) is completely filled with water and a cube of side \(1\,cm\) and density \(1.5\,g\,cm^{-3}\) is placed at the bottom of the tank. The work to be done to lift the cube at the bottom to a height of \(15\,m\) above the surface of water is:

A body of mass \(M\) is suspended from the lower end of an aeroplane accelerating horizontally. If the rope can withstand a maximum tension \(T\), then the maximum acceleration of the aeroplane is:

A uniform thin circular disc of mass \(M\) and radius \(R\) is shown in the figure. The moment of inertia of the shaded region about the diameter AB of the disc is:

Two brass spheres approaching each other with the same speed collide head-on elastically. After collision, if one of the spheres of radius \(R\) comes to rest, then the radius of the other sphere is:

The shift (in metre) in centre of mass when the largest possible equilateral triangular plate is removed from a uniform square plate of side \(2\,m\) with one of their sides coinciding is:

Two trains A and B are moving in the same direction with velocities \(V_A\) and \(V_B\) respectively and a third train C is moving in opposite direction. If velocity of C with respect to B is twice the velocity of A with respect to B, then velocity of A with respect to C is:

Law of conservation of mass was regarded as another basic conservation law of nature until the advent of:

Statement-I: When two quantities are multiplied, the relative error in the result is the sum of the relative errors in the quantities.
Statement-II: When two quantities are divided, the relative error in the result is the difference of the relative errors in the quantities.

The work function of Mg, Cu, Ag, Li are \(3.7, 4.8, 4.3, 2.5\,\text{eV}\) respectively. A wavelength of \(300\,\text{nm}\) light is shined on them. The metals which undergo photoelectric effect are

The half-life of a certain radio isotope is \(4\) minutes. The number of radioactive nuclei at a given instant is \(10^6\). Then the number of radioactive nuclei left \(2\) minutes later would be

Light of wavelength \(1000\AA\) incidents on a metal surface of work function \(6\,eV\). The maximum kinetic energy of photoelectrons is

The breakdown voltage of a zener diode is \(10\,V\). It is used in a voltage regulator circuit shown in figure. Current through zener diode is center

center

A carrier wave of frequency \(2\,MHz\) and peak voltage \(15\,V\) is used to modulate a message signal of frequency \(20\,kHz\) and peak voltage \(8\,V\). The frequencies of side bands produced are

A ball has a mass of \(50\,\text{g}\) and a speed of \(50\,\text{m s}^{-1}\). If the speed is measured within an accuracy of \(2\%\), then the uncertainty in its position (in m) is
\[ (h = 6.626 \times 10^{-34}\,\text{J s}, \ \pi = 3.14) \]

The energy of an electron in Bohr's hydrogen atom is \(-3.4\,eV\). The angular momentum of the electron is

In a coil the current varies from \(-3\,A\) to \(+3\,A\) in \(4\,s\), and induces an emf of \(0.2\,V\). The self inductance of the coil is

To have dissipative power in an LCR series circuit to be half

A material satisfies the relation \(\mu_0(H+M)=0\), where \(H\) and \(M\) are magnetic intensity and magnetization respectively; then the material is