Answer: 1:4.
- A 1:2
- B 1:4
- C 2:1
- D 4:1
Correct answer: B. 1:4
Explanation: Resistance is proportional to L/A. Thus R<sub>1</sub>:R<sub>2</sub> = (2/1):(1/2) = 4:1. In parallel the voltage is the same, so I<sub>1</sub>:I<sub>2</sub> = R<sub>2</sub>:R<sub>1</sub> = 1:4.
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.