⚡ Average EMF Induced in a Square Coil
📘 Question:
A square coil with 50 turns and side 20 cm is placed in a magnetic field that decreases from 0.9 T to 0.3 T in 0.15 s. Find the average emf induced in the coil.
✅ Step-by-Step Explanation:
🔹 Step 1: Given Values
- Turns (N) = 50
- Side = 0.20 m
- Bi = 0.9 T
- Bf = 0.3 T
- Δt = 0.15 s
🔹 Step 2: Area of the Square Coil
A = side² = (0.20)² = 0.04 m²
🔹 Step 3: Change in Magnetic Flux
ΔΦ = (Bf – Bi) × A = (0.3 – 0.9) × 0.04 = -0.024 Wb
🔹 Step 4: Apply Faraday’s Law
EMFavg = |N × ΔΦ / Δt| = |50 × (-0.024) / 0.15| = 8.0 V
🎯 Final Answer:
The average induced EMF is 8.0 V.
