Question

The heat generated in a circuit is dependent upon the resistance, current and time for which the current is flown. If the error in measuring the above are 1%, 2% and 1% respectively. The maximum error in measuring the heat is :

• A. 8%
• B. 6%
• C. 18%
• D. 12%

Answer 1

The correct option is B 6%

$Q=I^{2}Rt$

$\frac{\delta Q}{Q}=2\frac{\delta i}{i}+\frac{\delta R}{R}+\frac{\delta t}{t}$

$\frac{\delta Q}{Q}=2\times 2$ % $+1$%$+1$%

$\frac{\delta Q}{Q}=6$ %