Page 143 - Basic Electrical Engineering

Figure 2.38

The circuit diagram of two batteries supplying a common load has been
shown in Fig. 2.38.

Apply KVL to mesh ABEFA and BCDEB after arbitrarily showing the

branch current directions. Current through the batteries are I and I and
1
2
through the load is I + I , respectively, as has been shown.
1
2
From mesh ABEFA,

40 − 2I + 4 (I ) − 44 = 0
2
1
− 2I + 4I = − 40 + 44
2
1
2I − 4I = 40 − 44 or, 2I − 4I = −4 (i)
2
1
2
1
From mesh BCDEB

− 6(I + I ) + 44 − 4I = 0
2
2
1
− 6I − 10I = − 44 or, 6I + 10I = 44 (ii)
2
2
1
1
Students are once again reminded that while going through the loop or the
mesh, the following sign connection has been followed.

1. Moving from negative terminal towards positive terminal of a battery is considered positive
voltage, i.e., as voltage rise
2. Voltage drop in the resistor is taken as negative when moving in the direction of current flow.