Question

A coil of area 80 square cm and 50 turns is rotating with 2000 revolutions per minute about an axis perpendicular to a magnetic field of 0.05 Tesla. The maximum value of the e.m.f. developed in it is

• A. $200\pi volt$
• B. $\frac{10\pi}{3}volt$
• C. $\frac{4\pi}{3}volt$
• D. $\frac{2}{3}$volt

Answer 1

Answer: (C)

$\frac{4\pi}{3}volt$

Answer 2

$e = NBA\omega;\mspace{6mu}\omega = 2\pi f = 2\pi \times \frac{2000}{60}$

$\therefore\mspace{6mu} e = 50 \times 0.05 \times 80 \times 10^{- 4} \times 2\pi \times \frac{2000}{60} = \frac{4\pi}{3}$