Question

Two conducting wires of the same material and of equal lengths and equal diameters are first connected in series and then in parallel in a circuit across the same current. Find the ratio of heat produced in series and parallel combinations.

Answer 1

H= I^{2}RT, the current and time of consideration remains the same so ratio of heat is the ratio of resistances.
therefore,the ratio of heat produced=2R:R/2=4:1(series:parallel)