For the loops ‘ahdcba’
and ‘ahdefga’, the loop rules give –30I1 –
41 I3 + 45 = 0 and –30I1 + 21 I2 – 80 = 0 Example 3 5 A battery of 10 V and negligible internal resistance is
connected across the diagonally opposite corners of a cubical network
consisting of 12 resistors each of resistance 1 W (Fig 3