NEET Electromagnetic Induction — Set 20

Question 1

A coil with $ L = 0.1 \, \text{H} $ has its current increased from 0 to 4 A in 0.2 s. What is the energy stored?

Accepted Answer

Energy: $ W = \frac{1}{2} L I^2 $. $ W = \frac{1}{2} \times 0.1 \times (4)^2 = 0.05 \times 16 = 0.8 \, \text{J} $.

Question 2

A coil of self-inductance 0.5 H has its current increased from 1 A to 4 A in 0.25 s. What is the magnitude of the induced emf?

Accepted Answer

$ \varepsilon = L \frac{\Delta I}{\Delta t} $. $ \Delta I = 4 - 1 = 3 \, \text{A} $, $ \Delta t = 0.25 \, \text{s} $. $ \varepsilon = 0.5 \times \frac{3}{0.25} = 0.5 \times 12 = 6 \, \text{V} $.

Question 3

A coil of 260 turns rotates at 75 rad/s in a 0.05 T field. If the area is 0.018 m², what is the maximum emf?

Accepted Answer

$ \varepsilon_0 = N B A \omega = 260 \times 0.05 \times 0.018 \times 75 = 17.55 \, \text{V} $.

NEET Physics: Electromagnetic Induction — Practice Set 20

Q1. A coil with \( L = 0.1 \, \text{H} \) has its current increased from 0 to 4 A in 0.2 s. What is the energy stored?

Q2. A coil of self-inductance 0.5 H has its current increased from 1 A to 4 A in 0.25 s. What is the magnitude of the induced emf?

Q3. A coil of 260 turns rotates at 75 rad/s in a 0.05 T field. If the area is 0.018 m², what is the maximum emf?

Q4. A conducting disc rotates in a uniform magnetic field parallel to its axis. The induced emf between the center and rim arises due to what?

Q5. A conducting rod is stationary in a varying magnetic field. The induced emf in the rod arises due to which component of the force on its charges?

Q6. A coil of 320 turns rotates at 65 rad/s in a 0.08 T field. If the area is 0.015 m², what is the maximum emf?

Q7. A solenoid of 350 turns and length 0.7 m induces an emf of 1.2 V in a nearby coil when its current changes from 1 A to 4 A in 0.3 s. What is the mutual inductance?

Q8. A coil of 40 turns experiences a magnetic flux change from 0 to 0.01 Wb in 0.05 s. What is the induced emf?

Q9. A wheel with 9 spokes of 0.5 m each rotates at 55 rpm in a 0.6 T field. What is the induced emf?

Q10. A circular loop of radius 14 cm is deformed into a straight wire in a 0.15 T field in 0.5 s. What is the induced emf?