List of top Physics Questions

Which of the following is an example of a scalar quantity?
A coil of resistance 10 \( \Omega \) is connected to a battery of 12 V. If the current flowing through the coil is 2 A, what is the power dissipated in the coil?

In a hydraulic lift, the surface area of the input piston is 6 cm² and that of the output piston is 1500 cm². If 100 N force is applied to the input piston to raise the output piston by 20 cm, then the work done is _________  kJ.

A capacitor of capacitance 5 \(\mu\)F is charged to 100 V and then connected to an uncharged capacitor of 2 \(\mu\)F. What is the final potential difference across the capacitors?
Light consisting of two wavelengths 600 nm and 480 nm is used to obtain interference fringes in a double slit experiment. The screen is placed 1.0 m away from slits which are 1.0 mm apart. (i) Calculate the distance of the third bright fringe on the screen from the central maximum for wavelength 600 nm.
A block of mass 2 kg slides on a frictionless horizontal surface with a velocity of 3 m/s. It collides elastically with another block of mass 3 kg initially at rest. What is the velocity of the 2 kg block after the collision?
Two gases A and B are filled at the same pressure in separate cylinders with movable pistons of radii \(r_A\) and \(r_B\) respectively. On supplying an equal amount of heat to both the cylinders, their pressures remain constant and their pistons are displaced by 16 cm and 9 cm respectively. If the change in their internal energies is the same, then the ratio \(r_A / r_B\) is:
A 2 kg object is moving with a velocity of 5 m/s on a frictionless surface. It collides elastically with a stationary object of mass 3 kg. Find the velocity of the 3 kg object after the collision.
The work function of a metal is 2 eV. What is the threshold frequency for the photoelectric emission? (Take Planck's constant $ h = 6.63 \times 10^{-34} \, \text{Js} $, $ 1 \, \text{eV} = 1.6 \times 10^{-19} \, \text{J} $)
Two infinitely long straight wires ‘1’ and ‘2’ are placed \(d\) distance apart, parallel to each other, as shown in the figure. They are uniformly charged having charge densities \(\lambda\) and \(-\frac{\lambda}{2}\) respectively. Locate the position of the point from wire ‘1’ at which the net electric field is zero and identify the region in which it lies.
Two infinitely long straight wires ‘1’ and ‘2’ are placed d distance apart,
Two concave refracting surfaces of equal radii of curvature and refractive index 1.5 face each other in air as shown in figure. A point object O is placed midway, between P and B. The separation between the images of O, formed by each refracting surface is:
Two concave refracting surfaces of equal radii of curvature and refractive index

A 10 $\mu\text{C}$ charge is placed in an electric field of $ 5 \times 10^3 \text{N/C} $. What is the force experienced by the charge?

A wire of length 2 m and resistance 8 \(\Omega\) is stretched to double its original length, keeping the volume constant. What is the new resistance of the wire?
A bullet of mass $m$ moving with a velocity $u$ gets embedded in a block of mass $M$ initially at rest. If $\mu$ is the coefficient of friction between the block and the ground, then the displacement of the block due to the impact is:
A uniform circular disc of mass $\dfrac{\pi}{40}$ kg is rotating about an axis passing through its center and perpendicular to its plane with an angular speed of 150 rev/min. If the angular momentum of the disc is 6.25 Js, then its radius is:
Klystron valve is used to produce
A particle is executing simple harmonic motion with an amplitude of 10 cm. If the kinetic energy of the particle at a distance of 6 cm from the mean position is 100 J, then the kinetic energy of the particle at a distance of 2 cm from the mean position is
A drop of radius \( R \) breaks into \( n \) equal drops. What is the ratio of total final surface energy to initial surface energy?
When a metal wire of area of cross-section $1.5\times10^{-6}$ m$^2$ is subjected to a tension of 45 N, the decrease in its area of cross-section is $3\times10^{-10}$ m$^2$. If the Poisson’s ratio of the material of the wire is 0.4, the Young’s modulus of the material of the wire is:
Optical communication using fibres is performed in the frequency range of:
A train is moving with a speed of 198 kmph. If the distance between the rails is 120 cm and the vertical component of earth's magnetic field is $0.25 \times 10^{-4}$ T, the induced emf between the ends of the axle of the train is:
The displacement of a body executing simple harmonic motion is $y = 8\cos(\pi t)$ cm. The displacement of the body in the time interval between 1.5 s and 2.5 s is:
When three particles each having a positive charge $q$ are placed at the three vertices of an equilateral triangle, then the electrostatic force between any two particles is $F$. If a fourth particle of charge $3q$ is placed at the midpoint of one of the sides of the triangle, then the net electrostatic force on the fourth particle due to the remaining three particles is
A 132 V ac source is connected to a pure inductor of inductance 140 mH. If the frequency of the ac source is 50 Hz, then the current passing through the inductor is
If a 20 W bulb and a 100 W fan are used for 5 and 15 hours a day respectively, then the electrical energy consumed in a period of 30 days is: