A student discharged an 800 ?F capacitor in a simple RC circuit and used the dat
ID: 1261687 • Letter: A
Question
A student discharged an 800 ?F capacitor in a simple RC circuit and used the data recorded
to plot the graph shown on the next page, where Vc is the voltage of the capacitor and V0 is
the voltage of the battery. Calculate find the value of the resistor.
Explanation / Answer
For Disachrging a capacitor ,
V = Vo(e^(-t/RC))
Now ,
ln(V/Vo) = -t/RC
Hence , the slope in the graph is -1/RC
Here ,
slope = (-4.10 + 0.40)/(3.3 - 0.2)
slope = -37/31
Now , -1/RC = -37/31
1/(R*800 *10^-6) = 37/31
R = 1047.3 Ohm
the resistance is 1047.3 Ohm