Magnetic Effects & EMI Mock Tests

A particle of mass m and charge q moves in a uniform magnetic field B perpendicular to its velocity v. The radius of the circular path is R. If the charge is doubled and the mass is halved, keeping v and B the same, the new radius is:

A long straight wire carries current I. A rectangular loop of sides a and b (a parallel to the wire) is placed at distance d from the wire. The loop is moved away from the wire with constant speed v. The induced EMF in the loop is:

A circular coil of radius 10 cm has 100 turns. The magnetic field at the center when 1 A current flows is: (μ₀ = 4π × 10⁻⁷ T·m/A)

A long solenoid of n turns per unit length carries a current I. A circular loop of radius a and resistance R is placed coaxially inside the solenoid. If the current in the solenoid decreases uniformly from I to zero in time t, the total charge that flows through the loop is:

An infinitely long hollow cylinder of inner radius a and outer radius b carries a uniform current density J along its length. The magnitude of the magnetic field at a distance r from the axis (a < r < b) is:

A wire of length L carries a current I. It is bent into a circular coil of one turn. The same wire is then bent into a circular coil of two turns of equal size. The ratio of the magnetic field at the center of the two-turn coil to that of the one-turn coil is:

A long straight wire carries a current of 10 A. The magnetic field at a distance of 5 cm from the wire is: (μ₀ = 4π × 10⁻⁷ T·m/A)

A long straight wire carries a current I. A square loop of side a and resistance R is placed with its plane containing the wire, one side parallel to the wire at distance d. The loop is pulled away from the wire with constant speed v. The induced current in the loop at the instant when the near side is at distance d is: