00:01
We have a potential difference of 230 volts.
00:04
For part a, we want to know what is the resistance if we have a bulb with the power rating of 100 watts.
00:17
And so our equation would be power is equal to current times potential difference.
00:22
We don't know current, but we know we can find it using potential difference and resistance.
00:26
And so we can plug this into our equation where we get b squared.
00:32
Divided by resistance.
00:34
And so we're going to rearrange these.
00:35
So resistance is equal to potential different squared divided by power.
00:40
And so we have 230 squared divided by 100.
00:48
When you plug this in, you get 529 oms as a resistance.
00:55
Or b, we want to know the same thing, the resistance, but we want to know if it is a 60 -wad bulbs...