AIPMT-MAINS Physics Moving Charges and Magnetism Class 12 Questions

A proton carrying 1 MeV kinetic energy is moving in a circular path of radius R in uniform magnetic field. What should be the energy of an α-particle to describe a circle of same radius in the same field?

A magnetic needle suspended parallel to a magnetic field requires √3 J of work to turn it through 60°. The torque needed to maintain the needle in this position will be:

A short bar magnet of magnetic moment 0.4 JT⁻¹ is placed in a uniform magnetic field of 0.16 T. The magnet is in stable equilibrium when the potential energy is

A current loop consists of two identical semicircular parts each of radius R, one lying in the x-y plane and the other in x-z plane. If the current in the loop is i. The resultant magnetic field due to the two semicircular parts at their common centre is

A closely wound solenoid of 2000 turns and area of cross-section 1.5 × 10⁻⁴ m² carries a current of 2.0 Å. It is suspended through its centre and perpendicular to its length, allowing it to turn in a horizontal plane in a uniform magnetic field 5 × 10⁻² tesla making an angle of 30° with the axis of the solenoid. The torque on the solenoid will be

A bar magnet having a magnetic moment of 2 × 10⁴ JT⁻¹ is free to rotate in a horizontal plane. A horizontal magnetic field B = 6 × 10⁻⁴ T exists in the space. The work done in taking the magnet slowly from a direction parallel to the field to a direction 60° from the field is:

The magnetic force acting on a charged particle of charge -2 μC in a magnetic field of 2T acting in y direction, when the particle velocity is (2î + 3ĵ) × 10⁶ ms⁻¹, is: