Q.

If the percentage errors in measuring the length and the diameter of a wire are 0.1% each. The percentage error in measuring its resistance will be          [2024]

1 0.2%  
2 0.144%  
3 0.3%  
4 0.1%  

Ans.

(3)  

        R=ρLπd24

        RR=LL+2dd

        LL=0.1% and dd=0.1%

         RR=0.3%