Question

In ohm's experiment reading of voltmeter is $5.0\pm 0.2$ and reading of ammeter is $3.00\pm 0.06$. Find percentage error in $R$.

• A. 4%
• B. 3%
• C. 6%
• D. 8%

Answer 1

The correct option is C 6%

Error in voltmeter reading = $\frac{△V}{V}\times 100=\frac{0.2}{5}\times 100=\frac{20}{5}$ = 4%
Error in ammeter reading = $\frac{△I}{I}\times 100=\frac{.06}{3}\times 100$ = 2%
When two quantities are multiplied or divided, the relative error is the sum of the relative errors in the individual quantities.
$⟹\frac{△R}{R}\times 100=\frac{△V}{V}\times 100+\frac{△I}{I}\times 100$
= 4 + 2 = 6%