This page covers CAPF AC Moving Charges & Magnetism with complete concept notes, 18 graded practice MCQs, key points and exam-specific tips. Free to study.
18graded MCQs · easy to hard · full solution & trap analysis
A charged particle with charge q = 2 C moves with velocity v = 5 m/s perpendicular to a magnetic field B = 0.4 T. Calculate the magnetic force acting on the particle.
An electron moves in a circular path in a uniform magnetic field. If the magnetic field strength is doubled, what happens to the radius of the circular path?
A proton enters a magnetic field of 0.5 T at an angle of 30° to the field direction with speed 2 × 10⁶ m/s. The magnetic force on the proton is (charge of proton = 1.6 × 10⁻¹⁹ C):
Which of the following statements about the Lorentz force on a moving charge is correct?
A charged particle moves through crossed electric and magnetic fields without deflection. If E = 3 × 10⁵ V/m and B = 0.6 T, calculate the velocity of the particle.
A rectangular loop with sides 4 cm and 6 cm carries 2 A current in a uniform magnetic field of 1.5 T. The plane of the loop is parallel to the field. What is the net force on the loop?
An electron moves with speed 10⁷ m/s in a magnetic field of 0.1 T perpendicular to its motion. Find the angular frequency (cyclotron frequency) of its motion.
A dipole moment of 0.4 A·m² is placed in a magnetic field of 2 T at an angle of 60°. Calculate the torque on the dipole.
A solenoid has 200 turns and carries a current of 3 A. If the solenoid is 0.4 m long, find the magnetic field inside it.
A charged particle moves perpendicular to a uniform magnetic field with speed 2×10⁶ m/s. If the magnetic field strength is 0.5 T and the particle has charge 1.6×10⁻¹⁹ C and mass 1.67×10⁻²⁷ kg, find the radius of circular motion.
An electron enters a magnetic field of 2 T at an angle of 30° to the field direction with speed 3×10⁶ m/s. What is the radius of the helical path?
A proton and an alpha particle (He nucleus) are accelerated through the same potential difference and then enter perpendicular to a magnetic field. What is the ratio of their radii of curvature?
A current-carrying wire of length 0.5 m carrying 10 A is placed perpendicular to a magnetic field of 0.8 T. Calculate the force on the wire.
Two parallel wires carry currents of 5 A and 10 A in opposite directions. If they are separated by 20 cm, what is the nature of force between them?
A straight conductor of length 0.5 m carrying a current of 4 A is placed perpendicular to a uniform magnetic field of 2 T. Calculate the magnetic force acting on the conductor.
Two parallel conductors carry currents of 5 A and 3 A in the same direction, separated by a distance of 20 cm. What is the nature and magnitude of force per unit length between them?
An electron moves horizontally with velocity 2 × 10⁶ m/s perpendicular to a magnetic field of 0.01 T. What is the radius of the circular path traced by the electron? (Take m = 9.1 × 10⁻³¹ kg, e = 1.6 × 10⁻¹⁹ C)
A rectangular coil with 100 turns, area 0.02 m², carries a current of 2 A and is placed in a uniform magnetic field of 0.5 T at an angle of 60° to the field. Calculate the magnetic torque on the coil.