The equivalent resistance between A and B as shown in figure is:

Step-by-step solution

The equivalent circuit of the given configuration can be drawn as follows: With reference to the above diagram, the equivalent resistance of the given configuration can be calculated as follows: 1 R = 1 20   Ω + 1 20   Ω + 1 10   Ω = 1 5   Ω ⇒ R =   5 Ω