(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

You see this trace on your oscilloscope for an RC circuit. The vertical scale is 5volt/square and the horizontal scale is 50ms/square. What is the time constant of the RC circuit?

2. Relevant equations

Vc(t) = Vo(e^(-t/RC)

Vr(t) = -Vo * e^(-t/RC)

t halftime = Tln(2) = .69T

3. The attempt at a solution

So when the voltage is at its peak (15 V), that's Vo. and if I take that as V(t), it's V at 20 ms (approximately). Substituting this:

15 V = 15V(e^(.02/RC))

1 = e^-.02/RC

ln(1) = -.02/RC

0 = -.02/RC

Cross multiplying to solve here doesn't help me. Is there another formula I can use?

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Calculating time constant in RC Circuit

**Physics Forums | Science Articles, Homework Help, Discussion**