Physics A-Level
Time constant τ = RC
What Time constant τ = RC means in Physics A-Level, as defined for OCR.
Definition of Time constant τ = RC
Check what you remember
Read the wording for your board, then hide it and explain Time constant τ = RC in your own words. Rough notes are fine. This is a self-check, with no mark or grade.
Reference: OCR
The time for charge or current to fall to 1/e of its starting value, about 37%, found by multiplying resistance in ohms by capacitance in farads.
Topics that use Time constant τ = RC
- Charging and discharging capacitors (OCR A-Level)
Related terms
- Capacitor charging and discharging
- Circuit setup for capacitor investigations
- Current, charge and voltage graphs
- Differential equation for discharging a capacitor
- Discharging circuit
- Exponential charging and discharging
- Exponential decay and growth
- Exponential decay graph
Using Time constant τ = RC in the exam
Check the command word and mark scheme for your exact question. After comparing your explanation with the reference, use the term in an answer on the linked topic. This practice does not predict an exam mark.
Practise Physics questions
Create a free account to answer exam-style questions on this topic and get feedback on your answers.
Start free
All Physics A-Level termsA week of Premium from your first lesson · Then the free plan continues · No card, no charge