00:01
So, in this question, we will consider that the wire has a resistance of r initially, then r will be equal to rho l divided by a, where l is the length of the wire initially and a is the area of cross section of the wire initially, okay.
00:21
So this is the initial resistance of the wire.
00:25
Now, it is given to us that the length of the wire changes to 2 .2 times the original length of the wire.
00:35
So, the new length l dash is equal to 2 .2 times l.
00:39
Now, it is also given to us that the volume is a constant, volume is a constant.
00:49
So, we know that the volume is equal to area, cross sectional area into length, okay.
01:00
Now that the whole length has changed to 2 .2 l, the area should also be a dash multiplied by 2 .2 l or a dash must be equal to a divided by 2 .2, okay.
01:22
So, this should be the new area of the new wire, okay...