Question

In the circuit shown above, the current delivered by the 9-volt battery of internal resistance 1 ohm is 3 amperes. The power dissipated in R₂ is 12 watts.

a. Determine the reading of voltmeter V in the diagram.

b. Determine the resistance of R₂.

c. Determine the resistance of R₁.

Answer 1

a. V_T = E – Ir = 6 V

b. In parallel, each resistor gets 6 V and P = V²/R gives R = 3 Ω.

c. For the 3 Ω resistor we have I = V/R = 2 A leaving 1 A for the branch with R₁. R = V/I = 6 Ω.