Question

A wire is stretched so that its length becomes three times its original length. If its original resistance is 25 ohms, find the new resistance and resistivity.​

Answer 1

Answer:

Since, resistance is directly proportional to length,

R1/R2 = L1/L2

Therefore, 25 /R2= L/3L

Therefore R2= 75 ohm.

Note that resistivity does not change with change in dimensions.