List of top Physics Questions

A circular current loop of radius \( R \) is placed inside square loop of side length \( L \) (where \( L \gg R \)) such that they are co-planar and their centers coincide. The permeability of free space is \( \mu_0 \). The mutual inductance between the circular loop and square loop is _______.}

The figure given below shows an LCR series circuit with two switches \( S_1 \) and \( S_2 \). When switch \( S_1 \) is closed keeping \( S_2 \) open, the phase difference \( \phi \) between the current and source voltage is 30° and phase difference is 60° when \( S_2 \) is closed keeping \( S_1 \) open. The value of \( (3L_1 - L_2) \) is _______ H.}

One side of an equilateral prism is painted by a transparent material of refractive index \( n_2 \). The refractive index of prism is 1.6. The minimum value of \( n_2 \) required for total internal reflection from the painted face is _______.

An electromagnetic wave travels in free space along the x-direction. At a particular point in space and time, \( B = 2 \times 10^{-7} \hat{j} \) T is associated with this wave. The value of the corresponding electric field \( E \) at this point is _______ V/m.}

Two point charges \( 8 \, \mu C \) and \( -2 \, \mu C \) are located at \( x = 2 \, \text{cm} \) and \( x = 4 \, \text{cm} \), respectively on the x-axis. The ratio of electric flux due to these charges through two spheres of radii 3 cm and 5 cm with their centers at the origin is _______.

Two metal plates (A, B) are kept horizontally with separation of \( \frac{12}{\pi} \) cm, with plate A on the top.} An atomizer jet sprays oil (density \( 1.5 \, \text{g/cm}^3 \)) droplets of radius 1 mm horizontally. All oil droplets carry a charge 5 nC. The potentials \( V_A \) and \( V_B \) are required on plates A and B respectively in order to ensure the droplets do not descend. The values of \( V_A \) and \( V_B \) are _______. (Neglect the air resistance to the droplets and take \( g = 10 \, \text{m/s}^2 \))}

If an air bubble of diameter 2 mm rises steadily through a liquid of density 2000 kg/m³ at a rate of 0.5 cm/s, then the coefficient of viscosity of the liquid is _______ Poise.

Two resistors of 200 \( \Omega \) and 400 \( \Omega \) are connected in series with a battery of 100 V. A bulb rated at 200 W, 100 V is connected across the 400 \( \Omega \) resistance. The potential drop across the bulb is _______ V.}

A spherical ball of mass 2 kg falls from a height of 10 m and is brought to rest after penetrating 10 cm into sand. The average force exerted by sand on the ball is _______ N.}

A particle having charge \( 10^{-9} \, \text{C} \) moving in \( x \)-\( y \) plane in fields of \( 0.4 \hat{j} \, \text{N/C} \) and \( 4 \times 10^{-3} \hat{k} \, \text{T} \) experiences a force of \( \left( 4 \hat{i} + 2 \hat{j} \right) \times 10^{-10} \, \text{N} \). The velocity of the particle at that instant is _______ m/s.

The surface tension of a soap bubble is 0.03 N/m. The work done in increasing the diameter of bubble from 2 cm to 6 cm is \( \alpha \times 10^{-4} \) J. The value of \( \alpha \) is _______. (Take \( \pi = 3.14 \))}

A mixture of carbon dioxide and oxygen has volume 8310 cm³, temperature 300 K, pressure 100 kPa and mass 13.2 g. The number of moles of carbon dioxide and oxygen gases in the mixture respectively are _______.

Dimensions of universal gravitational constant (G) in terms of Planck's constant (h), distance (L), mass (M) and time (T) are:

A 0.5 kg mass is in contact against the inner wall of a cylindrical drum of radius 4 m rotating about its vertical axis. The minimum rotational speed of the drum to enable the mass to remain stuck to the wall (without falling) is 5 rad/s. The coefficient of friction between the drum's inner wall surface and mass is _______. (Take \( g = 10 \, \text{m/s}^2 \))}

A tub is filled with water and a wooden cube \(10\,\text{cm} \times 10\,\text{cm} \times 10\,\text{cm}\) is placed in the water. The wooden cube is found to float on the water with a part of it submerged in water. When a metal coin is placed on the wooden cube, the submerged part is increased by \(3.87\) cm. The mass of the metal coin is ____ gram. (Take water density \(=1\,\text{g/cm}^3\) and density of wood as \(0.4\,\text{g/cm}^3\)).}

A uniform wire of length \(l\) of weight \(w\) is suspended from the roof with a weight \(W\) at the other end. The stress in the wire at \( \frac{l}{3} \) distance from the top is} \[ \left(\frac{W}{A} + \frac{2}{\gamma}\frac{w}{A}\right) \] where \(A\) is the cross sectional area of the wire. The value of \(\gamma\) is ____.}

A \(1\,\mu\text{C}\) charge moving with velocity} \[ \vec{v} = (\hat{i} - 2\hat{j} + 3\hat{k}) \, \text{m/s} \] in the region of magnetic field} \[ \vec{B} = (2\hat{i} + 3\hat{j} - 5\hat{k}) \, \text{T} \] The magnitude of force acting on it is \( \sqrt{\alpha} \times 10^{-6} \) N. The value of \(\alpha\) is ____.}

Angular momentum of an electron in a hydrogen atom is \( \dfrac{3h}{\pi} \). Then the energy of the electron is ____ eV.

An electromagnetic wave travelling in \(x\)-direction is described by the field equation} \[ E_y = 300 \sin \omega\left(t - \frac{x}{c}\right). \] If the electron is restricted to move in \(y\)-direction only with speed \(1.5 \times 10^6\) m/s, then the ratio of maximum electric and magnetic forces acting on the electron is:

For a certain metal, when monochromatic light of wavelength \(\lambda\) is incident, the stopping potential for photoelectrons is \(3V_0\). When the same metal is illuminated by light of wavelength \(2\lambda\), the stopping potential becomes \(V_0\). The threshold wavelength for photoelectric emission for the given metal is \(\alpha \lambda\). The value of \(\alpha\) is:

A vessel contains \(0.15\,\text{m}^3\) of a gas at pressure \(8\) bar and temperature \(140^\circ\text{C}\) with \(c_p=3R\) and \(c_v=2R\). It expands adiabatically till pressure falls to \(1\) bar. The work done during this process is ____ kJ. (R is gas constant)}

A liquid drop of diameter \(2\) mm breaks into \(512\) droplets. The change in surface energy is \( \alpha \times 10^{-6} \) J. (Take surface tension of liquid = \(0.08\) N/m). The value of \(\alpha\) is ____.

For the given circuit (shown in part A) the time dependent input voltage \(v_{in}(t)\) and corresponding output \(v_o(t)\) are shown in parts (B) and (C), respectively. Identify the components that are used in the circuit between \(X\) and \(Y\).}

When a coil is placed in a time dependent magnetic field the power dissipated in it is \(P\). The number of turns, area of the coil and radius of the coil wire are \(N, A\) and \(r\) respectively. For a second coil the number of turns, area of the coil and radius of the coil wire are \(2N, 2A\) and \(3r\) respectively. If the first coil is replaced with second coil the power dissipated in it is \(\sqrt{2}\alpha P\). The value of \(\alpha\) is:

For a thin symmetric prism made of glass (refractive index \(1.5\)), the ratio of incident angle and minimum deviation will be _____.