JEE Physics - MCQ Practice Questions

A magnetic field B is applied perpendicular to a current-carrying wire of length L carrying current I. The magnetic force on the wire is F = BIL sin θ. What is the angle θ when the force is maximum?

The SI unit of magnetic field intensity is Tesla. One Tesla is equivalent to which of the following?

A solenoid with 500 turns is 0.5 m long and carries a current of 2 A. The permeability of free space is μ₀ = 4π × 10⁻⁷ T·m/A. Calculate the magnetic field inside the solenoid.

An electron moves in a circular path in a perpendicular magnetic field. Which quantity remains constant during its motion?

Two parallel wires carry currents I₁ = 5 A and I₂ = 3 A in the same direction, separated by distance r = 0.1 m. The force per unit length between them is approximately:

A rectangular loop ABCD with sides 2 m × 3 m carries a current of 4 A and is placed in a uniform magnetic field of 0.5 T perpendicular to the plane of the loop. The magnetic torque on the loop is:

A charged particle with charge q and mass m enters a magnetic field region with velocity v perpendicular to B. The radius of circular motion is given by:

A long straight wire carries a current and produces a magnetic field. At a distance of 2 cm from the wire, the field is 4 × 10⁻⁵ T. What is the current in the wire? (μ₀ = 4π × 10⁻⁷ T·m/A)

The magnetic dipole moment of a current loop is defined as m = NIA, where N is the number of turns, I is current, and A is area. If a circular loop of radius 5 cm carries 2 A current, the magnetic dipole moment is approximately:

A beam of electrons is accelerated through a potential difference V and then enters a region of perpendicular electric and magnetic fields. For the electrons to move undeflected, which condition must be satisfied?

The magnetic field at the center of a circular arc of radius R subtending angle θ at the center and carrying current I is:

A toroidal magnetic field is produced by a toroid with N turns carrying current I. If the mean radius of the toroid is R and the cross-sectional area of the core is A, the magnetic energy stored is:

An alpha particle (charge +2e, mass 4u) and a proton (charge +e, mass u) are accelerated from rest through the same potential difference. They then enter a uniform magnetic field perpendicular to their motion. The ratio of their radii of curvature is:

The magnetic flux through a surface is Φ = ∫B·dA. For a uniform field B perpendicular to a rectangular surface of area 2 m², with B = 0.5 T, the flux is:

According to Lenz's law, the induced EMF in a coil opposes the change in magnetic flux. If the flux through a coil increases at a rate of 0.1 Wb/s and the coil has 100 turns, the induced EMF is:

A conducting rod of length L = 0.5 m moves with velocity v = 10 m/s perpendicular to a uniform magnetic field B = 2 T. The motional EMF induced is:

In a cyclotron, a charged particle spirals outward as it gains energy. The frequency of revolution is independent of:

The magnetic field due to a solenoid inside and outside differs significantly. Which statement is correct?

A rectangular conducting loop is partially inside a uniform magnetic field region. If the loop is pulled out with constant velocity v, the induced EMF depends on:

The phenomenon where the inductance of a coil changes with the current flowing through it due to non-linear magnetic properties of the core is called: