00:01
Hello, in the question we have given that a simple rc circuit consists of a 1 microfarad capacitor.
00:09
So, the capacitance is given that is 1 microfarad.
00:13
We will convert it when we are solving it.
00:16
So, in series with 2800 ohm resistor, so the resistance is given that is equals to 2800 ohms.
00:28
So, this is the value of resistor.
00:31
A 6 volt battery, so the voltage is given that is equal to 6 volts and an open switch.
00:39
So, initially the capacitor is uncharged.
00:41
So, how long after switch is closed will the voltage across the capacitor be 4 .1.
00:48
So, now we will call this as v naught and v will be equal to 4 .1 v.
00:56
So, now in order to calculate this we will use the formula.
01:01
So, that is v is equals to v naught times 1 minus e raised to because this is the concept of charging of capacitor because when so initially it is uncharged.
01:12
So, if the switch is closed, so it will start charging.
01:16
So, this will be the formula.
01:18
So, this is the formula for charging of capacitor.
01:21
It is t by e raised to minus t by tau where tau is the time constant.
01:28
So, first of all we will calculate what is the time constant.
01:33
So, time constant tau is nothing but r times c.
01:37
So, tau will be equal to r is 2800 into c is 10 raised to minus 6.
01:44
So, this will become 2 .8 into 10 raised to minus 3 seconds.
01:55
So, this is the time constant...