List of top Physics Questions

A steel wire of length 1.25 m is stretched between two rigid supports. The tension in the wire produces an elastic strain of 0.14%. The fundamental frequency of the wire is (Density and Young's modulus of steel are $7.7 \times 10^3$ kgm$^{-3}$ and $2.2 \times 10^{11}$ Nm$^{-2}$ respectively)

The magnetic field due to current carrying circular loop of radius 6 cm at a point on the axis at a distance of 8 cm from centre is 27 $\mu$T. The magnetic field at the centre of the current carrying loop is.

A vessel contains 3 moles of He, 1 mole of Ar, 5 moles of N$_2$ and 3 moles of H$_2$. If the vibrational modes are ignored, the total internal energy of the system of gases is

A cylindrical tank having large diameter is filled with water to a height H. A hole of cross-sectional area 5 cm$^2$ in the tank allows water to drain out. If the water drains out at the rate of $2 \times 10^{-3$ m$^3$s$^{-1}$, then the value of H is} (acceleration due to gravity = $10$ ms$^{-2}$)

A monatomic gas ($\gamma = \frac{5}{3}$) at a pressure of 4 atm is compressed adiabatically so that its temperature rises from 27 $^\circ$C to 327 $^\circ$C. The pressure of the gas in its final state is

One end of the steel rod is clamped to the roof and the other end is attached to a mass of 1000 kg as shown in the figure. The length of the rod is 50 cm and its cross-sectional area is 1000 mm$^2$. The change in the length of the rod due to the weight of the mass is \underline{\hspace{2cm}} .

A circular film of a liquid has an area of 10 cm$^2$. If the work done in making its radius two times the initial radius is $8 \times 10^{-3$ J, the surface tension of the liquid is $\left(1+\frac{1}{a}\right)$ Nm$^{-1}$. The value of $a$ is}

A gas at 37 $^\circ$C is compressed adiabatically to half of its volume, then the final temperature of the gas is (Ratio of specific heat capacities of the gas is 1.5)

Assertion (A): In S.H.M kinetic and potential energy become equal when the distance is $\frac{1}{\sqrt{2}}$ times its amplitude. Reason (R): The potential energy of a particle executing S.H.M is periodic with time period being maximum at the extreme displacement.

As shown in the figure, two spherical cavities are made in the uniform solid sphere of radius R. The boundaries of the cavities touch at the centre of the sphere. The centers of the cavities and the sphere lie on the x-axis. The mass of the solid sphere before the cavities were created was M. The gravitational force on a point mass m at a distance 'd' away from the center of the solid sphere is

Two wooden blocks of mass M$_1$ and M$_2$ rest on a frictionless table. A bullet of mass m is fired at M$_1$ with speed v which embedded in it and the two together finally collide with M$_2$. Find the velocity of M$_2$ after collision. [Ignore any energy loss and treat the problem to be one dimensional]

An object of mass 20 kg. is displayed by $x = 5t^2$ m (here t is time) by the application of a force. Then the ratio of the work done in times 3 s and 5 s is

A uniform rod of length 60 cm is placed with one end in contact with the horizontal table and is then inclined at an angle 30$^\circ$ to the horizontal and allowed to fall. The angular velocity of the rod when it becomes horizontal is (acceleration due to gravity = 10 ms$^{-2}$)

A wheel undergoes a constant acceleration starting form rest at t = 0. The angular velocity of the wheel is 3.14 $\frac{\text{rad}}{\text{sec}}$ when t = 2 s. The accelerator is abruptly ceased at t = 20 s. The number of revolutions, wheel makes in the interval t = 0 to t = 40 s is

A physical quantity P is related to four observables a, b, c, and d as $ P = \frac{\sqrt{ab}.d^\alpha}{\sqrt{C}} $ ($\alpha$ is constant). The percentage errors in a, b, c and d are 0.5% in each. If the percentage error in P is 2%, then $\alpha$ is

Which of the following is true about the coefficient of static friction ($\mu_s$) and the coefficient of kinetic friction ($\mu_k$)

A box of mass 2 kg is placed on a inclined plane that makes 30$^\circ$ with the horizontal. The coefficient of friction between the box and inclined plane is 0.2. A force F is applied on the box perpendicular to the incline to prevent the box from sliding down. The minimum value of F is (acceleration due to gravity = 10 m s$^{-2}$)

A particle is moving on a circular path with a constant speed v. It's change of velocity as it moves from A to B in the figure is

A car is moving along a straight line is brought to a stop within a distance of 200 m and in time 10 s. The initial speed of the car is

A ball is thrown upward from the top of a building at an angle of 30$^\circ$ to the horizontal and with an initial speed of 20 m s$^{-1}$. If the ball strikes the ground after 3 s, then the height of the building is (acceleration due to gravity = 10 ms$^{-2}$)

The stopping potential ($V_0$) versus frequency ($\nu$) of a graph for the photoelectric effect in a metal is given. From the graph, the Planck's constant ($h$) is:

Young's double slit experiment is first performed in air and then in a medium other than air. It is found that the 9th bright fringe in the medium lies where the 5th dark fringe lies in the air, then the refractive index of the medium is:

If the charge on a capacitor is increased by 2 C, the energy stored in it increases by 44%. The original charge on the capacitor is (in C)

A Carnot engine has an efficiency of 50%. If the temperature of the sink is reduced by $ 40^\circ C $, its efficiency increases by 30%. The temperature of the source will be:

An electron in a hydrogen atom excites from $ n = 2 $ to $ n = 4 $. What is the change in angular momentum?
(Planck's constant $ h = 6.64 \times 10^{-34} \, \text{J s} $)