Electro Magnetic Induction And Alternating Currents Question 391
Question: The magnetic flux linked with a coil at any instant ?t? is given by f = 5t3 ? 100t + 300, the e.m.f. induced in the coil at t = 2 second is [KCET 2003]
Options:
A) ? 40 V
B) 40 V
C) 140 V
D) 300 V
Show Answer
Answer:
Correct Answer: B
Solution:
$ e=-\frac{d\varphi }{dt}=-\frac{d}{dt}( 5t^{3}-100t+300 ) $ $ =-(15t^{2}-100) $ at t = 2sec ; e = 40 V
