Electro Magnetic Induction And Alternating Currents Question 444
Question: A circular coil of mean radius of 7 cm and having 4000 turns is rotated at the rate of 1800 revolutions per minute in the earth’s magnetic field (B = 0.5 gauss), the maximum e.m.f. induced in coil will be [Pb. PMT 2003]
Options:
A) 1.158 V
B) 0.58 V
C) 0.29 V
D) 5.8 V
Show Answer
Answer:
Correct Answer: B
Solution:
$ e_{0}=\omega NBA=(2\pi \nu )NB(\pi r^{2}) $ $ =2\times {{\pi }^{2}}\nu \ NBr^{2} $ $ =2\times {{(3.14)}^{2}}\times \frac{1800}{60}\times 4000\times 0.5\times {{10}^{-4}}\times {{(7\times {{10}^{-2}})}^{2}} $ $ =0.58\ V $
