Question

The resistance of the network between the terminals A and B is:

• A. $30\Omega$
• B. $20\Omega$
• C. $50\Omega$
• D. $60\Omega$

Answer 1

The correct option is B $20\Omega$

[End two terminals of $5\Omega$ are neglected in this calculation because current doesn't flow through them when we apply voltage across AB]
Hence , $R_{AB}=\frac{(5+5+10)20}{40}+5+5=20\Omega$