Question

a wire is stretched so as to triple its length, if earlier resistance =R.what will b the new resistance ? ​

Answer 1

Dear Student ,
Earlier its resistance was $R=\frac{\rho L}{A}$
Now when the length is tripled then the resistance is $R\text{'}=\frac{\rho \times 3L}{A}=3\times \frac{\rho L}{A}=3R$ .
Regards