Physics
Physics
Problem
Which of the following situations will not produce an induced emf? a. A coil of wire in which an alternating current is flowing b. A single wire in which an alternating current is flowing c. A coil of wire in a circuit with a battery that is switched on d. A coil of wire in a circuit with a constant current flowingIntuitive explanation
The key here is Faraday's law of induction: an emf is induced only when the magnetic flux through a loop is changing. A stationary magnet, a loop at rest in a uniform field, or any scenario where stays constant will produce zero induced emf—even if a magnetic field is present. Look for the situation where nothing is moving, rotating, or changing in magnitude or direction.
Intuitive explanation
The key here is Faraday's law of induction: an emf is induced only when the magnetic flux through a loop is changing. A stationary magnet, a loop at rest in a uniform field, or any scenario where stays constant will produce zero induced emf—even if a magnetic field is present. Look for the situation where nothing is moving, rotating, or changing in magnitude or direction.