AIPMT-PRELIMS Physics Moving Charges and Magnetism Class 12 Questions

A right angle isosceles triangle ABC is placed in a uniform magnetic field acting along AB. If the magnetic force on the arm BC is \( \vec{F} \), the force on the arm AC is

There are four light-weight-rod samples, A, B, C, D separately suspended by threads. A bar magnet is slowly brought near each sample and the following observations are noted: (i) A is feebly repelled (ii) B is feebly attracted (iii) C is strongly attracted (iv) D remains unaffected. Which one of the following is true?

A square current carrying loop is suspended in a uniform magnetic field acting in the plane of the loop. If the force on one arm of the loop is \( \vec{F} \), the net force on the remaining three arms of the loop is

A thin ring of radius R meter has charge q coulomb uniformly spread on it. The ring rotates about its axis with a constant frequency of f revolutions/s. The value of magnetic induction in Wb/m² at the centre of the ring is

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:

Under the influence of a uniform magnetic field, a charged particle moves with constant speed V in a circle of radius R. The time period of rotation of the particle:

A particle of mass m, charge Q and kinetic energy T enters a transverse uniform magnetic field of induction B⃗ . After 3 seconds the kinetic energy of the particle will be -

A closed loop PQRS carrying a current is placed in a uniform magnetic field. If the magnetic forces on segments PS, SR and RQ are F₁, F₂ and F₃ respectively and are in the plane of the paper and along the directions shown, the force on the segment QP is :

A beam of electron passes undeflected through mutually perpendicular electric and magnetic fields. If the electric field is switched off, and the same magnetic field is maintained, the electrons move

A charged particle (charge q) is moving in a circle of radius R with uniform speed v. The associated magnetic moment μ is given by

Nickel shows ferromagnetic property at room temperature. If the temperature is increased beyond Curie temperature, then it will show

Under the influence of a uniform magnetic field a charged particle is moving in a circle of radius R with constant speed v. The time period of the motion

When a charged particle moving with velocity is subjected to a magnetic field of induction B, the force on it is non-zero. This implies that:

Two circular coils 1 and 2 are made from the same wire but the radius of the 1^{st} coil is twice that of the 2^{nd} coil. What is the ratio of potential difference applied across them so that the magnetic field at their centres is the same?

A coil in the shape of an equilateral triangle of side l is suspended between the pole pieces of a permanent magnet such that l is in plane of the coil. If due to a current i in the triangle a torque τ acts on it, the side l of the triangle is:

A very long straight wire carries a current I. At the instant when a charge +Q at point P has velocity \( \vec{v} \), as shown, the force on the charge is:

An electron moves in a circular orbit with a uniform speed v. It produces a magnetic field B at the centre of the circle. The radius of the circle is proportional to:

A long solenoid carrying a current produces a magnetic field B along its axis. If the current is doubled and the number of turns per cm is halved, the new value of the magnetic field is -

A charged particle moves through a magnetic field in a direction perpendicular to it. Then the

The magnetic field of given length of wire for single turn coil at its centre is 'B' then its value for two turns coil for the same wire is :-

An electron having mass 'm' and kinetic energy E enter in uniform magnetic field B perpendicularly, then its frequency will be:

For adjoining fig., The magnetic field at point, 'P' will be :

A charge having q/m equal to 10⁸ c/kg and with velocity 3 × 10⁶ m/s enters into a uniform magnetic field B = 0.3 tesla at an angle 30° with direction of field. Then radius of curvature will be :