List of top Physics Questions

An electric appliance supplies 6000 J/min heat to the system. If the system delivers a power of 90 W. How long it would take to increase the internal energy by $2.5 \times 10^3$ J ?

A body of mass 2 kg moving with a speed of 4 m/s makes an elastic collision with another body at rest and continues to move in the original direction but with one fourth of its initial speed. The speed of the two body centre of mass is $\frac{x}{10}$ m/s. Then the value of $x$ is ________.

A source producing sound of frequency 170 Hz is approaching a stationary observer with a velocity of 17 m/s. The apparent change in the wavelength of sound heard by the observer is (speed of sound in air = 340 m/s):

A particle of mass 10 kg is moving with a velocity of 5 m/s. The kinetic energy of the particle is:

The following circuit represents

The root mean square velocity of hydrogen molecules at 300 K is 1930 meters/second. The velocity of oxygen molecules at 1200 K will be:

A body executing SHM has displacement \( y = A \cos \omega t \). Identify the graph which represents the variation of potential energy (PE) as a function of time \( t \) and displacement.

A magnetic field of 5 T is applied perpendicular to a coil with 5 turns. The induced emf in the coil is 10 V. The rate of change of magnetic flux is:

A parallel plate capacitor with air between the plates has a capacitance of 3 μF. Calculate the capacitance if the distance between the plates is reduced by half and the space between them is filled with a substance of dielectric constant \( k \).

A string of length 3 m and mass 0.035 kg is stretched with a tension of 50 N. The speed of the wave on the string is:

A radioactive sample contains 5 × 10\(^7\) kg of each of two isotopes A and B with half-lives of 5 days and 8 days respectively. The fraction of A that decays in 3 days after a period of 3 days is:

Two point charges \( +3 \, \mu C \) and \( +8 \, \mu C \) repel each other with a force of 40 N. If a charge of \( -5 \, \mu C \) is added to each of them, then the force between them will become:

A sphere rolls down an inclined plane of inclination \( \theta \). What is the acceleration as the sphere reaches the bottom?

A given ray of light suffers minimum deviation in an equilateral prism P. Additional prisms Q and R of identical shape and same material such that P, Q, and R are now combined as shown in figure. The ray will now suffer

The current in the 120 \( \Omega \) resistor shown in the circuit is

Two bodies of the same mass are projected with the same velocity at an angle \( 30^\circ \) and \( 60^\circ \) respectively. The ratio of their horizontal ranges will be:

Photocathode work function is \( 1 \, \text{eV} \). Light of wavelength \( \lambda = 3000 \, \text{Å} \) falls on it. The photoelectron comes out with a maximum velocity of \( 1 \times 10^6 \, \text{m/s} \). What is the energy of the photon?

A steam engine operating between \( 100^\circ C \) and \( 40^\circ C \) has an efficiency of \( 25% \). The heat absorbed by the engine is:

Identify the correct statement.

Two wires A and B are of the same material. Their lengths are in the ratio \( 1:2 \) and the diameter is in the ratio \( 2:1 \). If they are pulled by the same force, then increase in length will be in the ratio of

A soap bubble of radius \( r_1 \) is placed on another soap bubble of radius \( r_2 \) (\( r_1<r_2 \)). The radius \( R \) of the soapy film separating the two bubbles is

Two spheres A and B of masses \( m \) and \( 2m \) and radii \( R \) and \( 2R \) respectively are placed in contact as shown. The COM of the system lies

If \( x = at + bt^2 \), where \( x \) is the distance travelled by the body in kilometers while \( t \) is the time in seconds, then the unit of \( b \) is