Question

A potential difference of V = 100 ± 2 volt, when applied across a resistance R gives a current of 10 ± 0.5 ampere. Calculate percentage error in R given by R = V/I.

Answer 1

Here. V = 100 ± 2 volt and I = 10 ± 0.5 ampere

Expressing limits of error as percentage error,

We have,

V = 100 volt ± \(\frac{2}{100}\) × 100% = 10 volt ± 2% and I = 10 ampere ± \(\frac{0.5}{10}\) × 100%

= 10 ampere ± 5%

∴ R = \(\frac{V}{I}\)

∴ %error in R = %error in V + %error in I

= 2% + 5% = 7%