Answer: 2 mV/cm.
- A 0.5 mV/cm
- B 1 mV/cm
- C 2 mV/cm
- D 5 mV/cm
Correct answer: C. 2 mV/cm
Explanation: Total voltage across wire = I x R = 2 x 4 = 8 V over 4 m = 400 cm. Potential gradient = 8/400 = 0.02 V/cm = 20 mV/cm. Hmm, let me recheck: 8V/400cm = 0.02V/cm = 2 mV/cm. Yes, 2 mV/cm.
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.