Question

Why there is a decrease in resistance when a parallel combination is used?

Answer 1

Explanation of resistance decrease:

1. When 2 resistors are connected in parallel the effective area of the resistor increases.
2. The resistance of the conductor is always inversely proportional to the area $R\propto \frac{1}{A}$.
3. Hence when the resistors are in parallel, the area increases, and resistance decreases.

Resistances in parallel combination:

1. When we have a parallel connection, each device is placed in its own branch. The electric charge has multiple paths to pass through the circuit.
2. When at a junction charges choose the path with minimum resistance. The charges reroute themselves such that the potential difference across conductors is the same
3. . If $R_1$ and$R_2$ are two resistance in parallel .The net resultant effective resistance is less than individual resistance $R_{parallel}=\frac{R_1{R}_2}{R_1+R_2}\le R_1,R_2$