Final answer:
Electromagnetic induction in a coil occurs due to a change in the magnetic field intensity which alters the magnetic flux, leading to the generation of an induced current. The correct answer is b) magnetic field intensity.
Step-by-step explanation:
Electromagnetic induction occurs in a coil when there is a change in magnetic field intensity. This phenomenon is a fundamental principle in electromagnetism and is given by Faraday's Law of Induction, which states that a change in magnetic flux induces an electromotive force (emf) and, hence, an electric field. There are several factors that can cause an induced current in a wire loop:
- Changing the strength of the magnetic field that passes through the coil
- Changing the size or shape of the wire loop within the magnetic field
- Changing the orientation of the wire loop relative to the magnetic field
When any of these actions occur, they change the magnetic flux through the loop, leading to the generation of an induced emf and consequently an induced current if the loop is part of a closed circuit.