⚡ Average EMF Induced in a Circular Coil
📘 Question:
A circular coil with a radius of 0.10 m and 40 turns lies in a uniform magnetic field. The field is perpendicular to the plane of the coil and decreases from 0.75 T to 0 T in 0.25 s. Calculate the average emf induced in the coil.
✅ Step-by-Step Explanation:
🔹 Step 1: Given Data
- Radius = 0.10 m
- Number of turns = 40
- Initial magnetic field = 0.75 T
- Final magnetic field = 0 T
- Time interval = 0.25 s
🔹 Step 2: Calculate Area
A = πr² = π × (0.10)² = 0.0314 m²
🔹 Step 3: Calculate Change in Magnetic Flux
Φinitial = B × A = 0.75 × 0.0314 = 0.02355 Wb
Φfinal = 0
ΔΦ = 0.02355 Wb
Φfinal = 0
ΔΦ = 0.02355 Wb
🔹 Step 4: Calculate EMF
EMFavg = (N × ΔΦ) / Δt = (40 × 0.02355) / 0.25 = 3.77 V
🎯 Final Answer:
The average induced EMF is 3.77 V.