Question

In an electric circuit shown, a network of resistors is connected across a cell of emf 2V and internal resistance 0.5 ohm 

(a) What is the total current drawn from the battery by the circuit? 

(b) What is the power consumed by the circuit from the battery?

Answer 1

(a) Equivalent network : 

 

Applying the principle of resistors in parallel and series: 

R_eq = 4/3 ohm 

Current is drawn from the cell due to total Resistance = 4/3 ohm + 0.5 ohm in series = 11/6 ohm 

V = R I 

So current drawn from the cell 

I = 2 x 6/11 = 12/11 A ≈ 1.1 

(b) Power consumed by the circuit = I²R = (12/11)² . (11/6) = 24/11 = 2.2 W