A) \[2\,\Omega \]
B) \[3\,\Omega \]
C) \[6\,\,\Omega \]
D) \[1\,\,\Omega \]
Correct Answer: B
Solution :
Key Idea: The bridge formed with given resistances is a balanced Wheatstone's bridge. The situation can be depicted as shown in figure. As resistances S and \[6\,\,\Omega \] are in parallel their effective resistance is \[\frac{6S}{6+S}\,\Omega \] As the bridge is balanced, hence it is balanced Wheatstone's bridge. For balancing condition, \[\frac{P}{Q}=\frac{R}{\left( \frac{6S}{6+S} \right)}\] \[or\frac{2}{2}=\frac{2(6+S)}{6S}\] \[or3\,S=6+S\] \[orS=3\,\Omega \]You need to login to perform this action.
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