List of top Physics Questions

A body of mass $ m $ and radius $ r $ rolling horizontally with velocity $ V $, rolls up an inclined plane to a vertical height $ \frac{V^2}{g} $. The body is:

A block of mass 5 kg is kept on a smooth horizontal surface. A horizontal stream of water coming out of a pipe of area of cross-section $ 5 \, \text{cm}^2 $ hits the block with a velocity of $ 5 \, \text{ms}^{-1} $ and rebounds back with the same velocity. The initial acceleration of the block is: (Density of water is $ 1 \, \text{g/cc} $) \vspace{0.5cm}

A capacitor of capacitance ‘C’ is charged to a potential ‘V’ and disconnected from the battery. Now if the space between the plates is completely filled with a substance of dielectric constant ‘K’, the final charge and the final potential on the capacitor are respectively:

A body of mass 10 kg is kept on a rough horizontal surface. If the force applied on the body is increased by 80 N, then the acceleration of the body increases by:

For a gas in a thermodynamic process, the relation between internal energy (U), the pressure (P), and the volume (V) is given by: \[ U = 3 + 1.5PV \] The ratio of the specific heat capacities of the gas at constant volume and constant pressure is:

At a pressure $ P $ and temperature $ 127^\circ C $, a vessel contains 21 g of a gas. A small hole is made into the vessel so that the gas leaks out. At a pressure of $ \frac{2P}{3} $ and a temperature of $ t^\circ C $, the mass of the gas leaked out is 5 g. Then $ t $ is:

A capacitor and a resistor are connected in series to an ac source. If the ratio of the capacitive reactance of the capacitor and the resistance of the resistor is 4:3, then the power factor of the circuit is:

A thin circular ring of mass 0.2 kg is rotating about its axis with an angular speed of 51 rad/s. Two particles having mass 2 g each are now attached at diametrically opposite points on the ring. Then the angular speed of the system is:

An object placed at a distance of 24 cm from a concave mirror forms an image at a distance of 12 cm from the mirror. If the object is moved with a speed of 12 ms$^{-1$, then the speed of the image is:} \vspace{0.5cm}

When the object and the screen are 90 cm apart, it is observed that a clear image is formed on the screen when a convex lens is placed at two positions separated by 30 cm between the object and the screen. The focal length of the lens is:

The magnetizing field which produces a magnetic flux of $22 \times 10^{-6} \, \text{Wb}$ in a metal bar of area of cross-section $2 \times 10^{-5} \, m^2$ is (susceptibility of the metal = 699):

A body of mass 3 kg is thrown vertically upward from the ground with a velocity of $ 10 \, \text{ms}^{-1} $. If the maximum height reached by the body is 4.7 m, then the loss of energy due to air resistance is:

A coil of 200 turns and area of cross-section $5 \times 10^{-3} \, m^2$ carries a current of 3 A. - The magnetic moment of the coil is

The following orbital energies ($E$) are compared. Identify the correct sets

(I) E₂(H) = E₂(H)
(II) E₃(H) = E₃(He)
(III) E₂s(H) < E₂s(He)
(IV) E₃s(He) < E₃s(H)

When an alternating voltage given by $E = 100 \sin(10^2 t)$, where $E$ is in volts and $t$ is in seconds, is applied across a capacitor of capacitance $20 \, \mu F$, the peak current flowing in the circuit is

If the wavelength of the incident radiation on a photosensitive metal surface is decreased from $3100 \, \text{Å}$ to $1550 \, \text{Å}$, the maximum kinetic energy of the emitted photoelectrons is tripled. - The work function of the metal surface is

An electron moving with a velocity of $4.8 \times 10^6 \, \text{ms}^{-1}$ enters a uniform magnetic field of $0.182 \, T$ in a direction perpendicular to the field. - The radius of the circular path in which the electron moves under the influence of the magnetic field is - (Mass of electron $= 9.1 \times 10^{-31} \, kg$ and charge of electron $= 1.6 \times 10^{-19} \, C$)

A $5$ kHz frequency signal is amplitude modulated on a carrier wave of frequency $2$ MHz. - One possible frequency of the resultant signal is

A gas mixture consists of 8 moles of argon and 6 moles of oxygen at temperature T. Neglecting all vibrational modes, the total internal energy of the system is

A coil of negligible resistance is connected in series with $90 \, \Omega$ resistor across $120 \, \text{V}, \, 60 \, \text{Hz}$ supply. A voltmeter reads $36 \, \text{V}$ across resistance. Inductance of the coil is:

An astronaut takes a ball of mass $ m $ from earth to space. He throws the ball into a circular orbit about earth at an altitude of 318.5 km. From earth's surface to the orbit, the change in total mechanical energy of the ball is $ x \frac{GM_em}{21R_e} $. The value of $ x $ is
(take $ R_e = 6370 \, \text{km} $):

Some energy levels of a molecule are shown in the figure with their wavelengths of transitions. Then:

A ring and a solid sphere roll down the same inclined plane without slipping. They start from rest. The radii of both bodies are identical and the ratio of their kinetic energies is $ \frac{7}{x} $ where $ x $ is $\_\_\_\_\_\_\_$.

Two identical conducting spheres P and S with charge Q on each, repel each other with a force 16N. A third identical uncharged conducting sphere R is successively brought in contact with the two spheres. The new force of repulsion between P and S is :

Consider a circuit where a cell of emf $ E_0 $ and internal resistance $ r $ is connected across the terminal A and B as shown in the figure. The value of $ R $ for which the power generated in the circuit is maximum, is given by: