00:01
Hello, in the question we have to define the maximum power transfer theorem.
00:08
So the maximum transfer theorem, it states that the maximum power that can be delivered from source to load resistance is equal to the source resistance.
00:17
In very simple terms, if we want maximum power, then this load resistance should be equal to the source resistance.
00:24
So that is what we have written over here.
00:26
That is rs is equal to rl.
00:28
Now, in the second part of the question, in the circuit shown below, determine the value of load resistance when load resistance draws maximum power.
00:37
Now the load resistance is drawing maximum power.
00:40
So for maximum power, we know this condition is there, that is rl is equal to rs.
00:45
So rl is 25 ohms.
00:48
So r equivalent turns out to be 50 ohms.
00:51
And if we find out the current, so current is v by r, because ohm's law is v is equal to ir.
00:57
So from there, i is v upon r equivalent.
01:00
And if we calculate, we get it as 1 amperes.
01:03
Further, the power, the formula is i squared r.
01:07
So that is 1 square plus 20 times 25, which gives us 25 watts.
01:14
Further, in the next part, so in the next part, we have this circuit given.
01:19
So they have given, saying that in the circuit diagram of figure below shows dry cells of emf 6 volt and the internal resistance of 2 .5 ohms.
01:29
So this is the internal resistance.
01:31
If the load resistance rl is varied from 0 to 5, so this rl can be varied from 0 to 5 ohms.
01:40
So in steps of 0 .5, so calculate the power dissipated by the load.
01:48
So now in each case, we will find out the power.
01:51
So now when first we will take rl as 0, so the power will turn out to be 0 watts.
01:58
Now, second one, rl is 0 .5 and the internal resistance is already 2 .5.
02:04
So the equivalent resistance i am doing for the first one in stepwise, but see r equivalent will be rl plus r.
02:13
So 0 .5 plus 2 .5, that is 3 ohms and the current will be v by r equivalent.
02:20
So this is 6 by 3, that is equal to 2 amperes.
02:24
So now we will also find out the potential.
02:27
So potential across, potential drop across rl is given by v is equals to i times rl.
02:34
So v is equal to 2 into 0 .5, that is 1 volts.
02:39
So power then turns out to be 2 watts because power is i times v.
02:46
This is the formula for power.
02:48
So it is iv.
02:49
So current we calculated, it is 2 amperes into 1 volt, so which gives us 2 watts.
02:58
Now we are making the rl load resistance to be 1, 1 ohms.
03:04
The internal resistance is already 2 .5...
