**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, R_{1} = 1 Ω, R_{2} = 2 Ω

Equivalent resistance = R_{1} + R_{2} = 1 + 2 = 3 Ω

Total current, I = V/R = 6/3 = 2A

Current through R_{2} = I_{2 }= I = 2A

Voltage across R_{2} = V_{2} = I_{2}R_{2 }= 2 × 2 = 4 Ω

Power used in R_{2} = I_{2} V_{2} = 2 × 4 = 8 W

(ii) V = 4 Volt, R_{1 }= 12 Ω, R_{2 }= 2 Ω

Voltage across R_{2} = V_{2} = V = 4V

Current across R_{2} = I_{2} = V_{2}/R_{2} = 4/2 = 2A

Power used in R_{2} = I_{2} V_{2} = 2 × 4 = 8 W