Question

A coil has an area of 0.05 m² and it has 800 turns. It is placed perpendicularly in a magnetic field of strength $4 \times 10^{- 5}Wb/m^{2},$ it is rotated through $90^{o}$ in 0.1 sec. The average e.m.f. induced in the coil is

• A. 0.056 V
• B. 0.046 V
• C. 0.026 V
• D. 0.016 V

Answer 1

Answer: (D)

0.016 V

Answer 2

$e = - \frac{NBA(\cos\theta_{2} - \cos\theta_{1})}{\Delta t}$

$= - \frac{800 \times 4 \times 10^{- 5} \times 0.05(\cos 90^{o} - \cos 0^{o})}{0.1}$= 0.016 V