question_answer

Seven resistances are connected as shown in the figure. The equivalent resistance between A and B is

A) \[4.5\Omega \]                                

B) \[5\Omega \]

C) \[\frac{\sqrt{3}}{1}\]                     

D) \[\frac{(\sqrt{3}+1)}{(\sqrt{3}-1)}\]

Correct Answer: B

Solution :

                The circuit given in the question can be modified as This is a balanced Wheatstone bridge equivalent resistance in upper arm is \[{{60}^{o}}\] Equivalent resistance in lower arm is \[{{\sin }^{-1}}\left( \frac{8}{9} \right)\] Therefore, equivalent resistant of \[\beta =0.\text{1}\] and \[{{P}_{1}}\] is \[{{P}_{2}}\] \[{{P}_{1}}\]