Question

In the given figure, the emf of the cell is 2.2 V, and if internal resistance is 0.6 Ω. Calculate the power dissipated in the whole circuit.

Options

• 2.2 W

• 1.32 W

• 0.65 W

• 4.4 W

Answer 1

2.2 W

Explanation:

Let us draw reduced circuit diagram,

In this diagram, the first end of each arm is connected to A, while the second end is connected to B. As a result, all arms are linked in parallel.

We can redraw it as follows:

Equivalent resistance for external resistance, R_eq

So, `1/(R_{eq}) = 1/R_1 + 1/R_2 + 1/R_3 + 1/R_4`

= `1/12 + 1/6 + 1/4 + 1/8`

R_eq = `8/5 = 1.6 Omega`

R_Net = R_eq + 0.6

= 1.6 + 0.6

= 2.2 Ω

Now, dissipate power = `V^2/R`

= `(2.2)^2/2.2`

= 2.2 W