Question

the voltage across the lamp is (6.0± 0.1) and the current passing through it is (4.0±0.2) ampere find the power consumed by the lamp

Answer 1

Voltage (V) = 6 V
(∆V) = 0.1 V
Current (I) = 4 A
∆I = 0.2 A

Power(p) = VI = 6×4 = 24 watt

Error in power :
$\frac{△p}{p}=\frac{△V}{V}+\frac{△I}{I}$

On substituting the value , we get
∆​p = 1.44 watt

Power is given by: (24$\pm$1.44) watt.