Electro Magnetic Induction And Alternating Currents Question 480
Question: A horizontal ring of radius $ r=\frac{1}{2}m $ is kept in a vertical constant magnetic field 1 T. The ring is collapsed from maximum area to zero area in 1 s. Then the emf induced in the ring is
Options:
A) 1 V
B) $ (\pi /4)V $
C) $ (\pi /2)V $
D) $ \pi ,V $
Show Answer
Answer:
Correct Answer: B
Solution:
- $ | . e | .=B\frac{dA}{dt} $ $ | . e | .=B\frac{(A_{2}-A_{1})}{(t_{2}-t_{1})}\Rightarrow | . e | .=\frac{1( \frac{\pi }{4}-0 )}{(1-0)} $ $ e=\frac{\pi }{4}V $
