Answer: 3:2.
- A 2:3
- B 4:3
- C 3:2
- D 3:4
Correct answer: C. 3:2
Explanation: Power delivered is P = E<sup>2</sup>R/(R + r)<sup>2</sup>. For 3 Ω, P<sub>1</sub> = 100 × 3/5<sup>2</sup> = 12 W. For 8 Ω, P<sub>2</sub> = 100 × 8/10<sup>2</sup> = 8 W. Thus P<sub>1</sub>:P<sub>2</sub> = 12:8 = 3:2.
In series, the same current flows through both resistors; in parallel, the current splits between branches and the voltage across each resistor is the same.
Concept context
Ohm's law, resistors, Kirchhoff's laws, Wheatstone bridge, and cells.