Solution
Related Formula
Ed = (B²)/(2μ₀), B = μ₀ n ICore Logic
Maximum current:
I₀ = (10)/(10) = 1 ACurrent at given instant:
I = (I₀)/(e) = (1)/(e)Energy density expression:
Ed = (μ₀ n² I²)/(2) = 4π × 10⁻⁷ × (10⁴)² × (1/e)²2 = (20π)/(e²) J/m³Therefore, α = 20.
Pattern Recognition
Sees: Energy density in inductor at exponential current growth stage. Shortcut: Express magnetic field B in terms of turns density n and current I, substitute into energy density formula Ed = (B²)/(2μ₀). Check: Numerical answer is 20. ✓
Chapter Mix
Class 12 Physics: Electromagnetic Induction