Page 115 - Basic Electrical Engineering

I R = (I − I )R 2
1
1 1
or, I (R + R ) = IR 2
2
1
1
or,

And,

or,

Thus, in a parallel circuit of two resistances, current through one branch is
equal to line current multiplied by the ratio of resistance of the other branch
divided by the total resistance as have been shown in (i) and (ii).

Example 2.3 Calculate the current flowing through the various resistances
in the circuit shown in Fig. 2.14.

Solution:

The circuit is reduced to a simple circuit through the following step: across
terminals A and B, the 4 Ω resistor is connected in parallel with two 2 Ω

resistor in series. Thus, we have two 4 Ω resistors connected in parallel across
terminal AB as has been shown in Fig. 2.15 (b). In Fig. 2.15 (c) is shown the

equivalent to two 4 Ω resistances in parallel. In Fig. 2.15 (d) is shown the
total resistance 4 Ω connected across the 12 V supply. The current is,