NEIEP Mechanics Practice Exam

When the speed of a wire moves through a magnetic field increases, what happens to the induced voltage?

1. It decreases

2. It remains the same

3. It increases

4. It becomes zero

The correct answer is: It increases

When the speed of a wire moving through a magnetic field increases, the induced voltage also increases. This phenomenon is explained by Faraday's law of electromagnetic induction, which states that the induced electromotive force (emf) in a circuit is directly proportional to the rate of change of the magnetic flux through the circuit. As the speed of the wire increases, it cuts through the magnetic field lines more rapidly, leading to a greater change in magnetic flux over time. This increased interaction with the magnetic field generates a higher induced voltage. Therefore, an increase in the speed at which the wire moves through the magnetic field results in an increase in the induced voltage.