question_answer

A thin wire of resistance \[4\Omega \] is bent to form a circle. The resistance across any diameter is

A)  \[4\Omega \]                   

B)  \[2\Omega \]

C)  \[1\,\Omega \]

D)  \[8\,\Omega \]

Correct Answer: C

Solution :

                 Given that the resistance of the total wire is \[4\Omega \] Here, \[\,ABC\,(2\Omega )\]and A\[ADB(2\Omega )\] are in parallel. So, the resistance across any diameter is \[\Rightarrow \]\[\frac{1}{R}=\frac{1}{2}+\frac{1}{2}=\frac{2}{2}=1\]\[\Rightarrow \]\[R=1\Omega \]