List of top Physics Questions

The velocity acquired by an electron at rest when subjected to a uniform electric field of potential difference $180~\text{V}$ is:
(Mass of electron $= 9 \times 10^{-31}$ kg and charge of electron $= 1.6 \times 10^{-19}$ C)
The energy stored in a capacitor is $W$. To double the charge on the plates of the capacitor, the additional work to be done is
In a region, the electric field is given by $\vec{E} = (3\hat{i} + 5\hat{j} + 7\hat{k})\ \text{N/C}$. The electric flux through a surface of area $3\ \text{m}^2$ in the $yz$-plane is (in SI units):
A light ray incidents on an equilateral prism made of material of refractive index $\sqrt{3}$. Inside the prism, if the light ray moves parallel to the base of the prism, then the angle of incidence of the light ray is:
A steel wire of length 81 cm has a mass of $5 \times 10^{-3}$ kg. If the wire is under a tension of 50 N, then the speed of transverse waves on the wire is:
If the ratio of specific heats of a gas at constant pressure and at constant volume is $\gamma$, then the number of degrees of freedom of the rigid molecules of the gas is
The fundamental limitation to the coefficient of performance of a refrigerator is given by
During adiabatic expansion, if the temperature of 3 moles of a diatomic gas decreases by \(50^\circ \text{C}\), then the work done by the gas is
(R - Universal gas constant)
A Carnot heat engine absorbs 600 J of heat from a source at a temperature of 127°C and rejects 400 J of heat to a sink in each cycle. The temperature of the sink is
If the values of the temperature of a body in Fahrenheit and Celsius scales are in the ratio of 13 : 5, then the temperature of the body is
In a hydraulic lift, if the radius of the smaller piston is \(5 \ \text{cm}\), and the radius of the larger piston is \(50 \ \text{cm}\), then the weight that the larger piston can support when a force of \(250 \ \text{N}\) is applied to the smaller piston is
The force required to stretch a steel wire of area of cross-section \(1 \ \text{mm}^2\) to double its length is
(Young’s modulus of steel \(= 2 \times 10^{11} \ \text{N/m}^2\))
When the mass attached to a spring is increased from 4 kg to 9 kg, the time period of oscillation increases by \(0.2\pi\) s. Then the spring constant of the spring is
For a particle executing simple harmonic motion, the ratio of kinetic and potential energies at a point where displacement is one half of the amplitude is
Three thin uniform rods each of mass \( M \) and length \( L \) are placed along the three axes of a Cartesian coordinate system with one end of all the rods at origin. The moment of inertia of the system of the rods about z-axis is
A thin uniform circular disc rolls with a constant velocity without slipping on a horizontal surface. Its total kinetic energy is
A body is projected at an angle of \(60^\circ\) with the horizontal. If the initial kinetic energy of the body is \(X\), then its kinetic energy at the highest point is
A body is moving along a straight line under the influence of a constant power source. If the relation between the displacement (s) of the body and time (t) is \(s \propto t^x\), then \(x =\)
Two balls each of mass 250 g moving in opposite directions each with a speed 16 m/s collide and rebound with the same speeds. The impulse imparted to one ball due to the other is
A train of mass \(10^6 \, \text{kg}\) is moving at a constant speed of \(108 \, \text{km/h}\). If the frictional force acting on it is \(0.5 \, \text{N per 100 kg}\), then the power of the train is
A particle crossing the origin at time \(t = 0\), moves in the xy-plane with a constant acceleration ‘a’ in y-direction. If the equation of motion of the particle is \(y = bx^2\) (where \(b\) is a constant), then its velocity component in the x-direction is
The magnitudes of two vectors are A and B (A>B). If the maximum resultant magnitude of the two vectors is ‘n’ times their minimum resultant magnitude, then \(\frac{A}{B} =\)
The ratio of the displacements of a freely falling body during second and fifth seconds of its motion is
The dimensional formula of Planck’s constant is
An unpolarised beam of light incidents on a group of three polarising sheets arranged such that the angle between the axes of any two adjacent sheets is $30^\circ$. The ratio of the intensities of polarised light emerging from the second and third sheets is