Question 210: Units , Dimensions and Error Analysis

Question

A copper wire is stretched to make it 0.5% longer. The percentage change in its electrical resistance if its volume remains unchanged is :

Accepted Answer

We know,
$R = {{ho l} \over A}$
and Volume (V) = A$l$
$ \Rightarrow $   A $=$ ${V \over l}$
$ 	herefore $   $R = {{ho {l^2}} \over v}$
$ 	herefore $   ${{\Delta R} \over R} = 2{{\Delta l} \over l}$
$=$   2 $ 	imes $ 0.5
$=$ 1%

Answer

2.0 %

Answer

2.5 %

Answer

1.0 %

Answer

0.5 %

Units , Dimensions and Error Analysis

A copper wire is stretched to make it 0.5% longer. The percentage change in its electrical resistance if its volume remains unchanged is :

Choose the correct answer: