Electrostatic Potential & Capacitance
Class 12 · Electrostatic Potential & Capacitance
RC Charging
q(t) = CV(1 − e^(−t/τ)). Watch the curve build with τ marked.
Key Notes
01
Charging through R: q(t) = CV(1 − e^(−t/τ)), τ = RC.
02
At t = τ: 63% of final charge. At 5τ: ≈ 99%.
03
Current decays as I = (V/R)e^(−t/τ).
Formulas
q(t)
τ = RC.
I(t)
Decreasing exponential.
Important Points
Larger R or larger C → slower charging.
Time constant τ has units of seconds (Ω · F = s).
RC Charging notes from sciphylab (also known as SciPhy, SciPhy Lab, SciPhy Labs, Physics Lab). Class 12 physics revision for JEE Mains, JEE Advanced, NEET UG, AP Physics 1/2/C, SAT, and CUET-UG.