NEIEP Mechanics Practice Exam

What factors determine the amount of induced voltage in a wire moving through a magnetic field?

1. Distance and direction of motion

2. Strength of the magnetic field and speed of the wire

3. Temperature and pressure

4. Size and shape of the wire

The correct answer is: Strength of the magnetic field and speed of the wire

The amount of induced voltage in a wire moving through a magnetic field is determined by the strength of the magnetic field and the speed of the wire. According to Faraday's law of electromagnetic induction, the induced electromotive force (EMF) in a circuit is directly proportional to the rate of change of the magnetic flux through the circuit. When a wire moves through a magnetic field, the interaction between the magnetic field and the moving charges within the wire generates voltage. A stronger magnetic field increases the magnetic flux and thus the induced voltage. Similarly, as the speed of the wire increases, it cuts through the magnetic lines of flux more rapidly, which corresponds to a greater change in magnetic flux over time and leads to a larger induced voltage. The other factors mentioned, such as distance and direction of motion, while they can have some impact, don't singularly and primarily determine the amount of induced voltage compared to the magnetic field strength and the speed of the wire. Additionally, temperature and pressure, as well as the size and shape of the wire, are not fundamental in determining the induced voltage in the context of electromagnetic induction and do not directly influence the key principles at play.