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Capacitors - Graph of lnV over t

Can someone explain to me why the gradient of lnV over t is 1/RC?

Ive tried rearranging the formula Vt = V0e^-t/RC but i end up with lnVt/V0 = -t/RC
but i dont know what to do from there?

Reply 1

username1560589

Original post by LotusTK

Can someone explain to me why the gradient of lnV over t is 1/RC?

Ive tried rearranging the formula Vt = V0e^-t/RC but i end up with lnVt/V0 = -t/RC
but i dont know what to do from there?

Have you studied log laws?

\log \frac{A}{B} = \log A - \log B

Reply 2

LotusTK

Original post by morgan8002

Have you studied log laws?

\log \frac{A}{B} = \log A - \log B

Oops. Ohh yes.

I think ive got it now. The formula we have is

lnVt = t x -1/RC + lnV0

where lnV0 is the y intercept.

This seems to match up to what im seeing on the graph.

Thanks, cant believe i didnt see the log rule in there.