Question

The net resistance of the circuit between points A and B as shown in the circuit below is: 3Ω m 20 www A 30Ω w B w 622 422​

Answer 1

In this case, the 2 resistors of 3 ohms and 2 ohms on the upper half of the circuit are connected in series and the combined resistance R1 is given as 3+2 = 5 ohms.

The 2 resistors of 6 ohms and 4 ohms on the lower half of the circuit are connected in series and the combined resistance R2 is given as 6+4 = 10 ohms.

The resistances R1, R2 and 30 ohms in the middle are connected in parallel. So the total resistance R of this parallel connection is given as

5

1

+

10

1

+

30

1

=

0.33

1

=3ohms. That is, the resistance in the closed loop is reduced to 3 ohms.

Hence, the value of the resistance in the circuit between A and B is 3 ohms.