Test

Solution

Correct: D

Magnetic field lines represent the direction and strength of the magnetic field. They originate at the north pole and terminate at the south pole outside the magnet, forming closed loops. They never intersect.

Solution

Correct: C

Fleming's Left-Hand Rule states that if the thumb, forefinger, and middle finger of the left hand are stretched perpendicular to each other, they represent the direction of force (motion), magnetic field, and current respectively.

Solution

Correct: A

Using the right-hand thumb rule, a clockwise current in a circular loop creates a magnetic field directed into the plane (opposite direction for counterclockwise).

Solution

Correct: B

The strength of an electromagnet depends on current, number of turns, and core material. Length of the core affects magnetic field strength only if it changes the coil geometry or core material distribution.

Solution

Correct: A

Lenz's Law states that the induced current direction opposes the change in magnetic flux that caused it, ensuring energy conservation.

Solution

Correct: C

An electric motor converts electrical energy into mechanical motion through the interaction of magnetic fields and current-carrying conductors.

Solution

Correct: A

Tesla is the SI unit defined as 1 N/(A·m²). Weber (Wb) is the unit of magnetic flux. Henry is related to inductance and Weber to flux.

Solution

Correct: A

Force F = I × L × B = 3A × 2m × 0.5T = 3 N. Direction is determined by right-hand rule.

Solution

Correct: B

Faraday’s Law of Electromagnetic Induction quantitatively relates induced emf to rate of change of magnetic flux.

Solution

Correct: A

Induced Eddy currents in the copper tube create opposing magnetic fields (Lenz’s Law), slowing the magnet. Thus, its acceleration is less than gravitational acceleration.