Question

Find the resistance and resistivity if a wire satreched so that the length becomes 3/2times of its original length if its original resistance is 20ohm

Answer 1

As resistance is directly proportional to length ...... we have the length increased by 3/2 time of the original length ... so even the resistance become 3/2 times of the original resistance...

ie. 20x 3/2 = 30 ohms( new resistance )