List of top Physics Questions

A transformer which steps down 330 V to 33 V is to operate a device having impedance 110 $\Omega$. The current drawn by the primary coil of the transformer is:

A spring of spring constant $ 200 \, {N/m} $ is initially stretched by $ 10 $ cm from the unstretched position. The work to be done to stretch the spring further by another $ 10 $ cm is:

A car travelling at 80 kmph can be stopped at a distance of 60 m by applying brakes. If the same car travels at 160 kmph and the same braking force is applied, the stopping distance is:

A slab consists of two identical plates of copper and brass. The free face of the brass is at $ 0^\circ C $ and that of copper at $ 100^\circ C $. If the thermal conductivities of brass and copper are in the ratio $ 1:4 $, then the temperature of the interface is:

125 identical charged small spheres coalesce to form a big charged sphere. If the electric potential on each small sphere is 60 mV, then the electric potential on the bigger sphere formed is:

A person climbs up a conveyor belt with a constant acceleration. The speed of the belt is $ \sqrt{\frac{g h}{6}} $ and the coefficient of friction is $ \frac{5}{3\sqrt{3}} $. The time taken by the person to reach from A to B with maximum possible acceleration is:

The maximum height attained by the projectile is increased by 10% by keeping the angle of projection constant. What is the percentage increase in the time of flight?

The acceleration of a particle which moves along the positive $ x $-axis varies with its position as shown in the figure. If the velocity of the particle is $ 0.8 \, \text{m/s} $ at $ x = 0 $, then its velocity at $ x = 1.4 \, \text{m} $ is:

The velocity of a particle is given by the equation $ v(x) = 3x^2 - 4x $, where $ x $ is the distance covered by the particle. The expression for its acceleration is:

A battery of emf $ 8V $ and internal resistance $ 0.5 \Omega $ is being charged by a $ 120V $ DC supply using a series resistor of $ 15.5 \Omega $. The terminal voltage of the $ 8V $ battery during charging is:

The acceleration of a particle which moves along the positive $ x $-axis varies with its position as shown in the figure. If the velocity of the particle is $ 0.8 \, {m/s} $ at $ x = 0 $, then its velocity at $ x = 1.4 \, {m} $ is: \includegraphics[]{83.png}

Two objects of masses 2 kg and 5 kg possess velocities $ 10 \hat{i} \, {m/s} $ and $ 3 \hat{i} + 5 \hat{j} \, {m/s} $ respectively. Then the velocity of C.M. in m/s is:

An electron is moving with a velocity $ (2\hat{i} + 3\hat{j}) $ m/s in an electric field $ (3\hat{i} + 6\hat{j} + 2\hat{k}) $ V/m and a magnetic field $ (2\hat{j} + 3\hat{k}) $ T. The magnitude and direction (with x-axis) of the Lorentz force acting on the electron is

In the Young's double slit experiment, the 2nd bright fringe for red light coincides with the 3rd bright fringe for violet light. Then the value of 'n' is: (Given: wavelength of red light = 6300 $\text{Å}$ and wavelength of violet light = 4200 $\text{Å}$)

E, m, L, G represent energy, mass, angular momentum and gravitational constant respectively. The dimensions of \[ \frac{EL^2}{mG^2} \] will be that of

A projectile can have the same range $ R $ for two angles of projection. Their initial velocities are the same. If $ T_1 $ and $ T_2 $ are times of flight in two cases, then the product of two times of flight is directly proportional to:

If \[ | \vec{P} + \vec{Q} | = | \vec{P} | = | \vec{Q} |, \] then the angle between $ \vec{P} $ and $ \vec{Q} $ is:

When an electron placed in a uniform magnetic field is accelerated from rest through a potential difference $ V_1 $, it experiences a force $ F $. If the potential difference is changed to $ V_2 $, the force experienced by the electron in the same magnetic field is $ 2F $, then the ratio of potential differences $ \frac{V_2}{V_1} $ is:

A 4 kg stone is attached to a steel wire being whirled at a constant speed of $ 12 $ m/s in a horizontal circle. The wire is 4 m long with a diameter of 2 mm, and Young’s modulus is $ 2 \times 10^{11} $ Nm$^2$. The strain in the wire is:

A spherical ball of radius $ 1 \times 10^{-4} $ m and density $ 10^4 $ kgm$^{-3}$ falls freely under gravity before entering water. The distance $ h $ before velocity change in water is:

An ideal gas is found to obey $ PV^{\frac{3}{2}} = \text{constant} $ during an adiabatic process. If such a gas initially at a temperature $ T $ is adiabatically compressed to $ \frac{1}{4} $th of its volume, then its final temperature is:

The condition $ dw = dq $ holds good in the following process:

The efficiency of a Carnot engine is found to increase from 25\% to 40\% on increasing the temperature ($T_1$) of the source alone through 100 K. The temperature ($T_2$) of the sink is given by:

The electric field intensity ($E$) at a distance of 3 m from a uniform long straight wire of linear charge density 0.2 $\mu C m^{-1}$ is:

A cell of emf 1.2 V and internal resistance 2 $ \Omega $ is connected in parallel to another cell of emf 1.5 V and internal resistance 1 $ \Omega $. If the like poles of the cells are connected together, the emf of the combination of the two cells is: