question_answer

A uniform wire of resistance\[9\,\Omega \]is cut into equal parts. They are connected in the form of equilateral triangle ABC. A cell of emf 2 V and negligible internal resistance is connected across B and C. Potential difference across AB is:

A)  1 V                        

B)         2 V                        

C)  3 V                        

D)         0.5 V

E)  0.25 V

Correct Answer: C

Solution :

\[R=\frac{9}{3}=3\,\Omega \] \[{{R}_{net}}=2\,\Omega \] PD across AB \[V=i\times R=\frac{V}{{{R}_{net}}}\times R\]                 \[=\frac{2}{2}\times 3=3V\]