\(A=(100 \pm 0.2) \,m^2\)
\(100=l^2 \Rightarrow l=10 \,m\)
\(\frac{\Delta A}{A}=\frac{2 \Delta l}{I}\)
\(\frac{0.2}{100}=2 \times \frac{\Delta l}{10}\)
\(\Rightarrow \Delta=0.01 \,m\)
So, length \(=(10 \pm 0.01) \,m\)
જયાં $B$ = ચુંબકીય ક્ષેત્ર, $l$ = લંબાઇ ,$m$ =દળ