Question:
Two conducting wires of the same material and of equal length and equal diameter are first connected in parallel and then in series in a circuit across the same potential difference. The ratio of heat produced in parallel and series combination is
Two conducting wires of the same material and of equal length and equal diameter are first connected in parallel and then in series in a circuit across the same potential difference. The ratio of heat produced in parallel and series combination is
Options:
- a) 2 : 1
- b) 4 : 1
- c) 1 : 2
- d) 1 : 4
- a) 2 : 1
- b) 4 : 1
- c) 1 : 2
- d) 1 : 4
correct answer : b)
Explanation:
Since both wires are identical, they have the same resistance R. In parallel, Rp = R/2. In series, Rs = 2R. Power P = V^2 / R. Ratio of power (parallel to series) = (V^2 / (R/2)) / (V^2 / 2R) = 4 : 1.
Since both wires are identical, they have the same resistance R. In parallel, Rp = R/2. In series, Rs = 2R. Power P = V^2 / R. Ratio of power (parallel to series) = (V^2 / (R/2)) / (V^2 / 2R) = 4 : 1.