The Magnitude of the induced emf in a coil is directly proportional to the rate of change of flux linkages. This is known as

Faraday's second law:

Faraday's second law of electromagnetic induction states that the magnitude of emf induced in the coil is equal to the rate of change of flux that linkages with the coil. 

The flux linkage of the coil is the product of the number of turns in the coil and flux associated with the coil.

\(E = - N\dfrac{{d\phi }}{{dt}}\)

Additional Information

Faraday’s first law:

• Faraday’s first law of electromagnetic induction states that whenever a conductor is placed in a varying magnetic field, emf is induced which is called induced emf. 
• If the conductor circuit is closed, the current will also circulate through the circuit and this current is called induced current.