Calculate the power used in the 2 resistor in each of the following circuits: (i) a 6 V … 4 V battery in parallel with 12 and 2 …
Answers:
(i) V = 6 Volt, R1 = 1 Ω, R2 = 2 Ω
Equivalent resistance = R1 + R2 = 1 + 2 = 3 Ω
Total current, I = V/R = 6/3 = 2A
Current through R2 = I2 = I = 2A
Voltage across R2 = V2 = I2R2 = 2 × 2 = 4 Ω
Power used in R2 = I2 V2 = 2 × 4 = 8 W
(ii) V = 4 Volt, R1 = 12 Ω, R2 = 2 Ω
Voltage across R2 = V2 = V = 4V
Current across R2 = I2 = V2/R2 = 4/2 = 2A
Power used in R2 = I2 V2 = 2 × 4 = 8 W