PHYSICS · Single correct · A Level · Physics · Electricity · Electricity
Problem
Two identical resistors, each of resistance R, are first connected in series to a battery and then reconnected in parallel to the same battery. Which statement best describes how the circuit’s equivalent resistance changes and why?
(a) It increases because connecting resistors in parallel adds them directly, giving R+R=2R.
(b) It decreases because additional paths allow more current for the same potential difference.
(c) It decreases because the potential difference across each resistor becomes half the battery emf.
(d) It remains the same because the total amount of resistor material is unchanged.