Acoil has 400 turns and self-inductance 7.50 mh. the current in the coil varies with time according to i = 1680 ma2 cos [πt/(0.0250s)].(a) what is the maximum emf induced in the coil? (b) what is the maximum average flux through each turn of the coil? (c) at t=0.0180s, what is the magnitude of the induced emf?

(a) 1.58 V

(b) 0.0126 Wb

(c) 0.0493 V

Solution:

As per the question:

No. of turns in the coil, N = 400 turns

Self Inductance of the coil, L = 7.50 mH =

Current in the coil, i = A

where

Now,

(a)  To calculate the maximum emf:

We know that maximum emf induced in the coil is given by:

For maximum emf, should be maximum, i.e., 1

Now, the magnitude of the maximum emf is given by:

(b) To calculate the maximum average flux,we know that:

(c) To calculate the magnitude of the induced emf at t = 0.0180 s:

e/c, where e is its total energy