List of top Physics Questions

Moment of Inertia of a thin uniform rod rotating about the perpendicular axis passing through its centre is $I$. If the same rod is bent into a ring and its moment of inertia about its diameter is $I'$, then the ratio ${\frac {I}{I'}}$ is
Following figures show the arrangement of bar magnets in different configurations. Each magnet has magnetic dipole moment $\overrightarrow{m}$ . Which configuration has highest net magnetic dipole moment?
When the energy of the incident radiation is increased by $20 \%, $ the kinetic energy of the photoelectrons emitted from a metal surface increased from 0.5 eV to 0.8 eV. The work function of the metal is
Figure shows a rectangular frame situated in a constant magnetic field. A wire BC of length \(1\text{ m}\) is moved out with velocity \(4\text{ m/s}\). Magnetic field strength is \(0.15\text{ T}\). Force acting on the wire \(BC\) is
A photon and an electron have an equal energy ' \(\text{E}\) '. The ratio of wavelength ' \(\lambda_\text{p}\) ' of photon to that of electron ' \(\lambda_\text{e}\) ' is proportional to
The height at which the acceleration due to gravity becomes \(\frac{g}{4}\) in terms of \(R\) is [ \(R = \text{the radius of the earth}\) ]
The equation of simple harmonic progressive wave is given by \(y = A \sin(100\pi t - 4x)\). The distance between two particles having a phase difference of \((\frac{\pi}{4})\) is
A fixed mass of gas at constant pressure occupies a volume ' \(V\) '. The gas undergoes a rise in temperature so that the r.m.s. velocity of the molecule is doubled. The new volume will be
In a biprism experiment, fifth dark fringe is obtained at a point. A thin transparent film of refractive index '\(\mu\)' is placed in one of the interfering paths. Now \(7^{\text{th}}\) bright fringe is obtained at the same point. If '\(\lambda\)' is the wavelength of light used, the thickness of film is equal to
The Boolean expression for \(\text{X-OR}\) gate \(C = (A \oplus B)\) is equivalent to
A transparent sphere of refractive index ' \(\mu\) ' and radius of curvature ' \(R\) ' is kept in air. A point object is placed at a distance ' \(d\) ' from the surface of the sphere so that the real image is formed at the same distance ' \(d\) ' from exactly opposite side of the sphere. The distance ' \(d\) ' is
A parallel combination of two capacitors of capacities ' \(C\) ' and ' \(\frac{C}{3}\) ' respectively is connected across a battery of 12 volt. When both capacitors are fully charged, the charge and energy stored in them is \(Q_1, Q_2\) and \(E_1, E_2\) respectively. Then the ratio of \((E_1 - E_2)\) to \((Q_1 - Q_2)\) is
A galvanometer of resistance ' \(G\) ' can be converted into a voltmeter of range \( (0 - V) \) volt by connecting a resistance ' \(R\) ' in series with it. The resistance ' \(R\) ' required to change its range from \( \left(0 - \frac{V}{4}\right) \) volt will be
The instantaneous value of current in an a.c. circuit is \(I = 2 \sin \left[ 100\pi t + \frac{\pi}{3} \right]\) A. The current will be maximum for the first time at \((\sin 90^\circ = 1)\)
A light metal disc of radius ' \(r\) ' floats on water surface and bends the surface downwards along the perimeter making an angle ' \(\theta\) ' with the vertical edge of the disc. If the weight of water displaced by the disc is ' W ', the weight of the metal disc is [ \(\text{T}\) = surface tension of water]
The magnetic field at the centre of a current carrying circular coil of area ' \(A\) ' is ' \(B\) '. The magnetic moment of the coil is ( \(\mu_0\) = permeability of free space)
The volume of a block of metal at \(30^\circ\text{C}\) changes by \(0.12\%\) when its temperature is increased to \(70^\circ\text{C}\). The coefficient of linear expansion of the metal is
In the diagram, the total electric flux through the closed surface 'S' is
[Given q = charge}
{\(\varepsilon_0 = \text{permittivity of free space}\)]
A solenoid having \(400\text{ turns/metre}\) has a core of a material with relative permeability \(300\). If a current of \(0.5\text{ A}\) is passed through it, then the magnetisation of the core material is nearly
A monoatomic ideal gas, initially at temperature ' \(T_1\) ' is enclosed in a cylinder fitted with a frictionless piston. The gas is allowed to expand adiabatically to a temperature ' \(T_2\) ' by releasing the piston suddenly. \(L_1\) and \(L_2\) are the lengths of the gas columns before and after the expansion respectively. Then \(\frac{T_1}{T_2}\) is
If an electron in hydrogen atom jumps from \(3^{\text{rd}}\) orbit to \(2^{\text{nd}}\) orbit it emits a photon of wavelength '\(\lambda\)'. When it emits a photon from \(4^{\text{th}}\) orbit to \(3^{\text{rd}}\) orbit then the corresponding wavelength of emitted photon will be
A solenoid is connected to a battery so that a steady current flows through it. If an iron core is inserted into the solenoid, then the current in the coil
A charged particle is subjected to acceleration in a cyclotron which consists of two dees '\(D_1\)' and '\(D_2\)'. The charged particle undergoes increase in its speed.
In thermodynamic process, which of the following statements is not true?
In case of well of death which is a vertical cylindrical wall of radius ' \(r\) ' inside which vehicle is driven in horizontal circles. If ' \(m\) ' is mass of vehicle, ' \(V\) ' is the velocity and ' \(\mu_s\) ' is the coefficient of static friction between the wheels of vehicle and walls then correct relation is [ \(g\) = acceleration due to gravity]