Electro Magnetic Induction And Alternating Currents Question 417
Question: A horizontal ring of radius $ r=1/2m $ 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:
- $ | \varepsilon |=B\frac{dA}{dt} $ $ | \varepsilon |=B\frac{(A_{2}-A_{1})}{(t_{2}-t_{1})} $ $ | \varepsilon |=\frac{1( \frac{\pi }{4}-0 )}{(1-0)} $ $ \varepsilon =\frac{\pi }{4}V $
