List of top Physics Questions

Which of the following laws is based on the principle of energy conservation?
Kilowatt-hour (kWh) is the unit of
Gauss’s law states that the electric flux through a closed surface is
The capacity of any condenser does not depend upon
If a conductor is placed in an external electric field, the field inside the conductor will be?
Which one of the following is the unit of capacity?
Two equal positive point charges of 1 μC charge are kept at a distance of 1 metre in air. The electric potential energy of the system will be.
A container has two chambers of volumes \(V_1 = 2\) litres and \(V_2 = 3\) litres separated by a partition made of a thermal insulator. The chambers contain \(n_1 = 2\) moles and \(n_2 = 3\) moles of ideal gas at pressures \(p_1 = 1\) atm and \(p_2 = 2\) atm, respectively. When the partition is removed, the mixture attains an equilibrium pressure of :
A car of mass 1000 kg is moving in a circular path of radius 50 m with a speed of 20 m/s. Calculate the centripetal force acting on the car.
State Lenz’s law. A rod MN of length \( L \) is rotated about an axis passing through its end M perpendicular to its length, with a constant angular velocity \( \omega \) in a uniform magnetic field \( \vec{B} \) parallel to the axis. Obtain an expression for emf induced between its ends.
Ruma reached the metro station and found that the escalator was not working. She walked up the stationary escalator with velocity \( v_1 \) in time \( t_1 \). On another day, if she remains stationary on the escalator moving with velocity \( v_2 \), the escalator takes her up in time \( t_2 \). The time taken by her to walk up with velocity \( v_1 \) on the moving escalator will be:
A body of mass 0.2 kg is attached to a light string of length 1 m and revolved in a vertical circle. What is the minimum speed at the lowest point so that the body can complete the circular motion? (Take \( g = 10 \, \text{m/s}^2 \))
“There is a limit to the amount of charge that can be stored on a given capacitor.” Explain.

Match List-I with List-II 
\[\begin{array}{|l|l|} \hline \text{List-I (Physical Quantity)} & \text{List-II (Units)} \\ \hline \text{(A) Magnetic field} & \text{(I) J T\(^{-1}\)} \\ \hline \text{(B) Magnetic moment} & \text{(II) T m A\(^{-1}\)} \\ \hline \text{(C) Pole strength} & \text{(III) J T\(^{-1}\) m\(^{-1}\)} \\ \hline \text{(D) Permeability of free space} & \text{(IV) Wb m\(^{-2}\)} \\ \hline \end{array}\]Choose the correct answer from the options given below: 
 

A proton accelerated through a potential difference of V volts has a de-Broglie wavelength \(\lambda\) associated with it. In order to get the same wavelength associated with an \(\alpha\)-particle, the required accelerating potential is
In the following nuclear reaction, \(^1_0\text{n} + ^{235}_{92}\text{U} \rightarrow ^{140}_{54}\text{Xe} + ^b_a\text{Sr} + 2(^1_0\text{n})\) we have
Which of the following statement(s) is/are true for p-type semiconductors?
(A) Holes are minority carriers and pentavalent atoms are the dopants.
(B) Electrons are majority carriers and trivalent atoms are the dopants.
(C) Holes are majority carriers and trivalent atoms are the dopants.
(D) Electrons are minority carriers and pentavalent atoms are the dopants.
Choose the correct answer from the options given below:
On connecting a device X in a series circuit with a battery and a resistor, a current passes through the circuit. On reversing the polarity of the battery, the current in the circuit drops to almost zero. The device X may be a
Below given are some statements about electronic devices:
(A) Diodes can be used for rectifying an ac voltage.
(B) For semiconductors, band gap energy E\(_g\) > 3 eV.
(C) By changing the external applied voltage, junction barriers can be changed.
(D) p-n junction is the 'key' to all semiconductor devices.
Choose the correct answer from the options given below:
An electron in the ground state of a hydrogen atom absorbs 12.09 eV energy. The angular momentum of the electron increases by
Which of the following statements are correct?
(A) The electrostatic repulsive force between the protons can be greater than the nuclear force to bind the nucleons together inside a nucleus.
(B) The repulsive electrostatic force between protons in smaller nuclei is much smaller than the nuclear force between nucleons inside a nucleus.
(C) The gravitational force between nucleons is much smaller than the nuclear force between the nucleons inside a nucleus.
(D) The binding energy per nucleon between nucleons is almost constant because the nuclear force is a long range force.
Choose the correct answer from the options given below:
The de-Broglie wavelength associated with a ball of mass 150 g traveling at 30.0 m/s would be
Which of the following statements are correct?
(A) A nucleus of mass number A has a radius R given by the expression R = R\(_0\)A\(^{1/3}\)
(B) Volume of nucleus is proportional to mass number A
(C) The density of nucleus increases with the radius of nucleus.
(D) Density of nuclear matter does not depend on its mass number A
Choose the correct answer from the options given below:
The photoelectric current is directly proportional to the number of photo electrons emitted per second. This implies that
A polaroid sheet is rotated between two crossed polarizers. The intensity of transmitted light would be maximum, when the angle between the axes of the first polarizer and the polaroid sheet is