Ohms law states that voltage drop is , where
is resistance and
is the current.
Here voltage is constant.
\Consider .
.
Apply derivative on each side by considering voltage as constant.
\.
Relative error in current is
.
Substitute and
in
.
Therefore, relative error in current is approximately same in magnitude as the relative error in resistance .
Relative error in current is approximately same in magnitude as the relative error in resistance .