Answer :
Answer:
magnet being moved into or out of the coil
Explanation:
Electromagnetic induction occurs when there is a change in the magnetic flux through a closed coil of wire; when this occurs, an emf (electromotive force) is induced in the coil, and it is given by
[tex]\epsilon= -\frac{\Delta \Phi}{\Delta t}[/tex]
where
[tex]\Delta \Phi[/tex] is the variation of magnetic flux through the wire
[tex]\Delta t[/tex] is the time elapsed
From the formula, we see that an emf (and so, a current) is induced in the coil of wire only if there is a change in the magnetic flux through the coil. Among the options given, only the following one:
magnet being moved into or out of the coil
involves a change in the magnetic flux through the coil (because by moving the magnet into and out the coil, we change the strenght of the magnetic field crossing the area enclosed by the coil), so this is the right answer.