Resistors are
connected in parallel when more than one resistors are connected in such a way
that they branch out from a single point (known as a node), and join up again
at another point in the circuit.
connected in parallel when more than one resistors are connected in such a way
that they branch out from a single point (known as a node), and join up again
at another point in the circuit.
Examples of three
resistor connected in parallel are shown in figure 1 and 2 below.
resistor connected in parallel are shown in figure 1 and 2 below.
Please
note that the node does not have to be physically a single point; as long as
the current has more than one point to flow through, then that part of the
circuit is considered to be in parallel. Figure 1 and 2 though different in
appearance are identical circuits.
note that the node does not have to be physically a single point; as long as
the current has more than one point to flow through, then that part of the
circuit is considered to be in parallel. Figure 1 and 2 though different in
appearance are identical circuits.
At
point A, the potential is the same for equal resistors. Similarly, at B, the
potential is the same for each resistor. So between point A and B, the
potential difference is the same. That is, each of the three resistors in
parallel has the same voltage across them
point A, the potential is the same for equal resistors. Similarly, at B, the
potential is the same for each resistor. So between point A and B, the
potential difference is the same. That is, each of the three resistors in
parallel has the same voltage across them
V = V1 = V2 = V3 – – – – (1)
Where
V is the total voltage applied to the parallel circuit, and V1, V2,
and V3 are voltage drops across R1, R2, and R3
respectively.
V is the total voltage applied to the parallel circuit, and V1, V2,
and V3 are voltage drops across R1, R2, and R3
respectively.
The
total current splits at A and travels through each of the resistors and reunite
at B. Assuming that the total current is I and that through R1,R2,and
R3 are I1,I2,and I3 respectively,
then
total current splits at A and travels through each of the resistors and reunite
at B. Assuming that the total current is I and that through R1,R2,and
R3 are I1,I2,and I3 respectively,
then
I = I1 + I2 + I3 – – – – – (2)
By
applying Ohm’s law to (2), we have
applying Ohm’s law to (2), we have
