Question Detail
Question
In a charging RC circuit, what fraction of the initial current (I₀) is flowing after one time constant (τ)?
Correct Answer
Option A is the correct answer.
Detailed Explanation
Page 21 states that after one time constant, the 'Current drops to 1/e of initial value (about 36%)'. Mathematically, at t = τ, i(τ) = I₀ e⁻¹ ≈ I₀ * 0.3678.
Hint
Use the formula i(t) = I₀ e⁻ᵗ/ᴿᶜ and substitute t = τ.