Electro Magnetic Induction And Alternating Currents Question 392
Question: A coil has 1,000 turns and 500 cm2 as its area. The plane of the coil is placed at right angles to a magnetic induction field of $ 2\times {{10}^{-5}},Wb/m^{2} $ . The coil is rotated through $ 180^{o} $ in 0.2 seconds. The average e.m.f. induced in the coil, in milli-volts, is [EAMCET 2003]
Options:
A) 5
B) 10
C) 15
D) 20
Show Answer
Answer:
Correct Answer: B
Solution:
By using $ e=-\frac{NBA( \cos {\theta_{2}}-\cos {\theta_{1}} )}{\Delta t} $ $ e=-\frac{1000\times 2\times {{10}^{-5}}\times 500\times {{10}^{-4}}( \cos 180^{o}-\cos 0^{o} )}{0.2} $ $ ={{10}^{-2}}volt=10mV $
