Two heater coil made of the same material are connected in parallel ac...
Heater Coil Comparison
Introduction
When two heater coils made of the same material are connected in parallel across the mains, the length and diameter of the wire of one of the coils are doubled than the other. In this scenario, we need to determine which one of the coils will produce more heat.
Explanation
The amount of heat produced by a heater coil is directly proportional to the resistance of the wire and the square of the current passing through it. The resistance of a wire is directly proportional to its length and inversely proportional to its cross-sectional area. That means, if the length of the wire is doubled, its resistance will also be doubled. On the other hand, if the diameter of the wire is doubled, its cross-sectional area will be quadrupled, and its resistance will be reduced to one-fourth of its original value.
Calculation
Let's assume that the resistance of the smaller coil is R, and its current is I. The resistance of the larger coil will be 2R, and its current will be I/2 (because the total current is divided equally between the two coils). Therefore, the power dissipated by the smaller coil will be I^2R, and the power dissipated by the larger coil will be (I/2)^2 x 2R = 0.5I^2R. As we can see, the power dissipated by the smaller coil is higher than that of the larger coil.
Conclusion
In conclusion, the heater coil with a smaller length and diameter will produce more heat than the one with a larger length and diameter when connected in parallel across the mains. This is because the resistance of the smaller coil is less, and it can dissipate more power due to its higher current.