NEET Electromagnetic Induction — Set 10

Question 1

A solenoid with mutual inductance 0.15 H has a current change of 8 A/s in the primary coil. What is the induced emf in the secondary coil?

Accepted Answer

$ \varepsilon = M \frac{dI}{dt} = 0.15 \times 8 = 1.2 \, \text{V} $.

Question 2

A rod rotates at 22 rad/s in a 0.4 T field. If the length from the axis to the tip is 0.6 m, what is the emf induced?

Accepted Answer

$ \varepsilon = \frac{1}{2} B \omega R^2 $. $ \varepsilon = \frac{1}{2} \times 0.4 \times 22 \times (0.6)^2 = 1.584 \, \text{V} \approx 1.58 \, \text{V} $.

Question 3

A coil with a high self-inductance is connected to a battery. Why does the current take time to reach its maximum value?

Accepted Answer

High self-inductance induces a back emf that opposes the increase in current, slowing the rate at which the current builds up to its steady-state value.

NEET Physics: Electromagnetic Induction — Practice Set 10

Q1. A solenoid with mutual inductance 0.15 H has a current change of 8 A/s in the primary coil. What is the induced emf in the secondary coil?

Q2. A rod rotates at 22 rad/s in a 0.4 T field. If the length from the axis to the tip is 0.6 m, what is the emf induced?

Q3. A coil with a high self-inductance is connected to a battery. Why does the current take time to reach its maximum value?

Q4. A coil is connected to a DC source via a switch. When the switch is opened, a spark is observed. This is due to what phenomenon?

Q5. A rectangular loop of sides 25 cm and 10 cm moves out of a 0.5 T field at 1.5 m/s perpendicular to the longer side. What is the motional emf?

Q6. A coil of 120 turns experiences a magnetic flux change from 0 to 0.04 Wb in 0.08 s. What is the induced emf?

Q7. A square loop of side 24 cm rotates at 15 rad/s in a 0.25 T field. What is the maximum emf induced?

Q8. A rectangular loop of 0.26 m × 0.42 m moves out of a 0.45 T field at 0.7 m/s along its shorter side. What is the emf?

Q9. A metal plate swings like a pendulum through a magnetic field. The slowing of its motion is primarily due to what?

Q10. A coil with \( L = 0.35 \, \text{H} \) has its current increased from 0 to 5 A in 0.5 s. What is the energy stored?