FAA Aviation Mechanic General (AMG)Fundamentals of Electricity and ElectronicsMedium
A technician moves a wire loop rapidly through a magnetic field. According to Faraday's Law of electromagnetic induction, the magnitude of the induced EMF in the loop is directly proportional to what factor?
- AThe ambient air temperature surrounding the loop
- BThe total length of the wire loop
- CThe rate of change of magnetic flux through the loop
- DThe resistance of the wire loop
Show answer & explanationAnswer & explanation
Correct answer: C. The rate of change of magnetic flux through the loop
Faraday's Law states that induced EMF is proportional to the rate of change of magnetic flux linking the circuit. Moving the loop faster through the field increases this rate of change, increasing the induced voltage.
Why the other options are wrong
- A. Temperature has no direct relationship to electromagnetic induction.
- B. Wire length affects resistance, not directly the induced EMF magnitude per Faraday's Law.
- D. Resistance affects current flow, not the EMF generated by induction.
Faraday's Law of Induction
States that the induced EMF in a conductor is directly proportional to the rate of change of magnetic flux through the circuit.
- Faster relative motion increases induced EMF
- Basis for generator and transformer operation
- Formula: EMF = -N(dΦ/dt)
Memory trick: Faster flux change = bigger spark — speed matters, not wire length.