question_answer

The equivalent resistance between A and B is :

A) 10 \[\Omega \]                                

B) 20 \[\Omega \]

C) 30 \[\Omega \]                                

D) 40\[\Omega \]

Correct Answer: A

Solution :

The given circuit is a balanced wheat stone bridge. So, resistance connected across diagonal will be meaningless. Equivalent resistance of upper arms\[{{R}_{1}}=10+10=20\,\Omega \] \[{{R}_{1}}\]and\[{{R}_{2}}\]are in parallel, so,\[{{R}_{AB}}=\frac{{{R}_{1}}{{R}_{2}}}{{{R}_{1}}+{{R}_{2}}}=\frac{20\,20}{2020}=10\,\Omega \]