Correct Answer - Option 4 : 100 V
Concept:
-
Self-inductance: The property of the current-carrying coil to resists the change of current flowing through it.
- This occurs mainly due to the self-induced emf produced in the coil itself.
\(⇒ L=N\frac{ϕ}{I}\)
Where N = number of turns in the coil, L = self-inductance of the coil, ϕ = flux associated with the coil and I = current in the coil
-
Mutual - inductance: Current is induced in secondary coil kept in proximity with the coil carrying current.
- This property of inducing a current in the secondary coil by changing the flux of the secondary coil is called mutal inductance.
\(⇒ M =N_{1}\frac{\phi }{I_{2}}\)
M is mutual inductance between Coil 2 and 1, N1 is the number of turns in coil 1, ϕ is magnetic flux induced in coil 2.
- The induced emf in the secondary coil is given as
\(E = M\frac{di }{dt}\)
Calculation:
Given Mutual inductance M = 1. 25 Henery
Rate of change of current \(\frac{di }{dt} = 80 \) A
Emf induced E = 1.25 H × 80 A/s = 100 Volt
So, induced emf is 100 V.