Question

Magnetic field of $2 \times 10 ^{\sim 2} Wb rrr^2$ is acting at right angle to a coil of area 1,000 cm² having 50 turns. This coil is removed from the field in 1/10s. Find the magnitude of induced emf.

Answer 1

magnetic field acts at right angle to a coil , B = 2 × 10^-2 Wb/m²

cross sectional area of the coil, A = 1000 cm² = 1000 × 10^-4 = 0.1 m²

number of turns , N = 50

a/c to question, the coil is removed from the magnetic field in 1/10 sec .

so, change in magnetic flux =number of turns × change in magnetic field × Area

= N × (final magnetic field - initial magnetic field) × A

= 50 × (0 - 2 × 10^-4) × 0.1

= - 10^-3 Wb

now, induced emf = - change in magnetic flux/time
= -(-2 × 10^-3)/(1/10)

= 2 × 10^-2 V