A resistor R has a nominal stated value of 100 5 percent A

A resistor R has a nominal stated value of 100 ± 5 percent. A voltage E is impressed on the resistor, and the power dissipation across this resistor is to be calculated. Calculate the uncertainty in the power determination when the measured values of E and I are points) E=40 V ± 2 % and 1-5A±1% Clearly show your solution method.

Solution

E= 40 +/- 2%= 40 +/- (2*40)/100 = 40 +/- 0.8
R= 100 +/- 5% = 100 +/- (5*100)/100 = 100 +/- 5
I= 5A +/- 1% = 5 +/- (1*5)/100 = 5 +/- 0.05
Power= (E^2)/R= (1600/10000) +/- (2*0.8+5) = 0.16 +/- 6.6