00:01
Here you have a capacitor that's not charged connected to a resistor and the resistor has a resistance of 100 oms.
00:12
The capacitance of the capacitor is 20 times 10 to the minus 6 ferrets and both of these are connected to a battery which has an emf or a voltage of 9 volts.
00:28
And we want to calculate a few things.
00:31
So we want to calculate first the time constant of the circuit, which is found by the equation, the time constant, which is the variable tau, is equal to resistance times capacitance.
00:43
We know both those values, so you can easily plug them in and get the answer.
00:47
Part b, we want to find the maximum charge that the capacitor can store, and that's found by capital q is equal to the capacitance of the capacitor, times the emf or the voltage of the battery.
01:02
And finally, for part c, you want to find the charge that's stored in the capacitor after one second.
01:10
And that's found by the equation q.
01:12
The charge stored in the capacitor is equal to capital q, the maximum charge times 1 minus e to the minus t divided by the time constant r times c.
01:25
So once we know the time constant from part a, the maximum charge that the capacitor can store in part b, we can plug in our values and find the amount of charge stored in one second...