Question

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. (a) 5%
• A. (b) 7%
• A. (c) 5.2%
• A. (d) $\frac { 5 } { 2 }$ %

Answer 1

(b)

Sol. $\therefore$ $\left( \frac { \Delta R } { R } \times 100 \right) _ { \max } = \frac { \Delta V } { V } \times 100 + \frac { \Delta I } { I } \times 100$

$= \frac { 5 } { 100 } \times 100 + \frac { 0.2 } { 10 } \times 100$ $= ( 5 + 2 ) \%$ = 7%