question_answer

In the circuit shown here, E1 = E2 = E3 = 2 V and R1 = R2 = 4 ohms.  The current flowing between points A and B through battery E2 is                                                                   [MP PET 2001]

A)            Zero

B)            2 amp from A to B

C)            2 amp from B to A

D)            None of the above

Correct Answer: B

Solution :

                   The given circuit can be redrawn \[{{E}_{eq}}=\frac{{{E}_{1}}{{R}_{2}}+{{E}_{2}}{{R}_{1}}}{{{R}_{1}}+{{R}_{2}}}=\frac{2\times 4+2\times 4}{4+4}=2V\] and \[{{R}_{eq}}=\frac{4}{2}=2\Omega \]. Current \[i=\frac{2+2}{2}=2A\] from A to B through E2