List of practice Questions

A galaxy is moving away from the Earth so that a spectral line at 6000 Å is observed at 6300 Å. Then the speed of the galaxy with respect to the Earth is

A uniform magnetic field of strength \( B = 2 \, \text{mT} \) exists vertically downwards. These magnetic field lines pass through a closed surface as shown in the figure. The closed surface consists of a hemisphere \( S_1 \), a right circular cone \( S_2 \), and a circular surface \( S_3 \). The magnetic flux through \( S_1 \) and \( S_2 \) are respectively

In the figure, a conducting ring of certain resistance is falling towards a current-carrying straight long conductor. The ring and conductor are in the same plane. Then the

An induced current of 2 A flows through a coil. The resistance of the coil is 100 \( \Omega \). What is the change in magnetic flux associated with the coil in 1 ms?

A square loop of side length \( a \) is moving away from an infinitely long current-carrying conductor at a constant speed \( v \) as shown. Let \( x \) be the instantaneous distance between the long conductor and side AB. The mutual inductance \( M \) of the square loop - long conductor pair changes with time \( t \) according to which of the following graphs?

Which of the following combinations should be selected for better tuning of an LCR circuit used for communication?

A coil having 9 turns carrying a current produces a magnetic field \( B_1 \) at the centre. Now the coil is rewound into 3 turns carrying the same current. Then the magnetic field at the centre \( B_2 \) is:

A particle of specific charge \( \frac{q}{m} \) is projected from the origin towards the positive x-axis with the velocity \( 10 \, \text{m/s} \) in a uniform magnetic field \( B = -2 \hat{k} \, \text{T} \). The velocity \( v \) of the particle after time \( t = 5 \, \text{ms} \) will be (in m/s)

The magnetic field at the centre of a circular coil of radius \( R \) carrying current \( I \) is 64 times the magnetic field at a distance \( x \) on its axis from the centre of the coil. Then the value of \( x \) is

Magnetic hysteresis is exhibited by magnetic materials.

Magnetic susceptibility of Mg at 300 K is \( 1.2 \times 10^{-5} \). What is its susceptibility at 200 K?

A cube of side 1 cm contains 100 molecules each having an induced dipole moment of \( 0.2 \times 10^{-16} \, \text{C} \cdot \text{m} \) in an external electric field of \( 4 \times 10^4 \, \text{N/C} \). The electric susceptibility of the materials is ___

A capacitor of capacitance 5$\mu$F is charged by a battery of emf 10V. At an instant of time, the potential difference across the capacitors is 4V and the time rate of change of potential difference across the capacitor is 0.6 V/s. Then the time rate at which energy is stored in the capacitor at the instant is

\( \overrightarrow{E} \) is the electric field inside a conductor whose material has conductivity \( \sigma \) and resistivity \( \rho \). The current density inside the conductor is \( \overrightarrow{j} \). The correct form of Ohm's law is

In the circuit shown, the end A is at potential \( V_0 \), and end B is grounded. The electric current indicated in the circuit is

The I-V graph for a conductor at two different temperatures 100°C and 400°C is as shown in the figure. The temperature coefficient of resistance of the conductor is about (in per degree Celsius)

For a particle executing simple harmonic motion (SHM), at its mean position:

A motor-cyclist moving towards a huge cliff with a speed of 18 km/h, blows a horn of source frequency 325 Hz. If the speed of the sound in air is 330 m/s, the number of beats heard by him is

A body has a charge of \( -3.2 \mu C \). The number of excess electrons it has is

A point charge A of +10\mu C and another point charge B of +20\mu C are kept 1m apart in free space. The electrostatic force on A due to B is \( \overrightarrow{F}_1 \), and the electrostatic force on B due to A is \( \overrightarrow{F}_2 \). Then

A uniform electric field \( E = 3 \times 10^3 \, \text{N/C} \) is acting along the positive Y-axis. The electric flux through a rectangle of area \( 10 \, \text{m} \times 30 \, \text{m} \), where the plane of the rectangle is parallel to the Z-X plane is

The total electric flux through a closed spherical surface of radius \( r \) enclosing an electric dipole of dipole moment \( 2aq \) is (Give \( \epsilon_0 \) = permittivity of free space)

Under electrostatic condition of a charged conductor, which among the following statements is true?

A blanking operation is performed on C20 steel sheet to obtain a circular disc having a diameter of 20 mm and a thickness of 2 mm. An allowance of 0.04 is provided. The punch size used for the operation is _____mm (rounded off to 2 decimal places).

Find the odd one out in the set: {19, 37, 21, 17, 23, 29, 31, 11}