00:01
So in this problem we have an rc circuit with an emf or a voltage of 12 volts, a resistance of 175 oms, and capacitance of 55 .7 microference or times 10 to the minus 6 ferrets.
00:26
So for part a, we want to find the time constant.
00:29
So the time constant is just tau equals resistance times capacitance.
00:37
So we have both of those values, so we just plug it in and we find the time constant of the circuit.
00:42
For part b, we want to find the maximum charge that's building up on the capacitor.
00:49
And for that, we use the equation, the charge q equals the capacitance times the emf or the voltage of the battery.
00:57
And then for part c, you want to find the initial current of the capacitor, meaning the current at t equals zero.
01:09
To do that, you have an equation for the current on a capacitor, which is given as i of t equals the emf divided by the resistance times e to the minus t divided by tau.
01:24
So for a, looking for the time constant tell, which is just resistance times capacitance.
01:35
So we have 175 times the capacitance 55 .7 times 10 to minus 6...