Question

I have lab in about an hour so please reply as soon as you can :)

RC Circuits

Show why the plot of “ln V/V_o vs. t” results in a straight line. What is the physical meaning for the slope of this line?

Answer 1

if it is charging RC circuit then u know  

V =Vo *( 1-e^t/RC)

V/Vo = 1- e^-t/RC

ln(V/Vo) = ln( 1-e^-t/RC) no straight line so i guess your question asking about discharging  

in discharging

V =Vo *e^-t/RC

V/Vo = e^-t/RC

ln( V/Vo) = ln( e^-t/RC) = -t/RC ( bcz ln(e^x) = x*lne = x)

ln( V/Vo) = -1/RC *t which is clearly a straight line

with slope -1/RC = 1/tau = -1/time cosntant

Physics meaning

by calculating slope of straight line u can calulate time constant of circuit

Plz rate the answer & let me know in comment if there is any problem or doubt