Answer: 0.068.
- A 0.034 Ω
- B 0.17 Ω
- C 0.068 Ω
- D 0.34 Ω
Correct answer: C. 0.068 Ω
Explanation: Using R = ρL/A, with A = 0.5 × 10<sup>-6</sup> m<sup>2</sup>, R = (1.7 × 10<sup>-8</sup> × 2)/(0.5 × 10<sup>-6</sup>) = 0.068 Ω.
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.