Q. The resistance $R = \frac{V}{i}$ where $V = 100 \pm 5\ volts$ and $i = 10 \pm 0.2\ amperes$. What is the total error in $R$
A) $5\%$
B) $7\%$
C) $5.2\%$
D) $\frac{5}{2}\%$
Explanation
$\therefore\ \left( \frac{\mathrm{\Delta}R}{R} \times 100 \right)_{\max} = \frac{\mathrm{\Delta}V}{V} \times 100 + \frac{\mathrm{\Delta}I}{I} \times 100$ $= \frac{5}{100} \times 100 + \frac{0.2}{10} \times 100 = (5 + 2)\% = 7\%$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.