Parallel Combination of Resistors
Two or more resistors are said to be connected in parallel when the voltage is the same across all the resistors. In such circuits, the current is branched out (divided) and recombined when branches meet at a common point. Here, a resistor or any other component can be connected or disconnected easily without affecting other elements in a parallel circuit.
Figure : Resistors in parallel combination.
In the given parallel connection, the total effective resistance,
The sum of reciprocals of resistance of an individual resistor is the total reciprocal resistance of the system.
EXAMPLE
From Example 3.1, Let the two resistors of 100 Ω & 200 Ω be connected in a parallel combination in a circuit. Find the total resistance due to this parallel combination.
Solution: Given, R 1 = 100 Ω & R 2 = 200 Ω.
For parallel combination,
1 / R total = 1 / (100 Ω) + 1 / (200 Ω)
R = 66.67 Ω
ie, the parallel combination of the 100 Ω & 200 Ω resistors gave a total effective resistance of 66.67 Ω.