Answer : Electromagnetic induction
Explanation :
In Nineteenth century English scientist Michael Faraday found that if he moved a magnet through a loop of wire, an electric current flowed in that wire.
He gives the relation ship between the magnetic field and the electric current to produce electromagnetic force (EMF). The EMF is given as :
[tex]\epsilon=-N\dfrac{d\phi}{dt}[/tex]
Where,
N is the number of turns
[tex]\dfrac{d\phi}{dt}[/tex] is the rate of change of magnetic flux
[tex]\phi=B.A[/tex]
B is the magnetic field
A is the area of cross section
So, the correct option is (B) "electromagnetic induction"
