question_answer

The potential difference between points A and B is:

A)  \[\frac{20}{7}V\]                            

B)         \[\frac{40}{7}V\]                            

C)         \[\frac{10}{7}V\]                                            

D)         zero

Correct Answer: D

Solution :

From the given figure, current through lower branch of resistance which are joined in series is                 \[{{i}_{1}}=\frac{10}{4+3}=\frac{10}{7}A\] Again current through upper branch of resistance which are also connected in series, is                 \[{{i}_{2}}=\frac{10}{8+6}=\frac{10}{14}A\] Now, according to the Kirchhoffs voltage law                 \[{{V}_{B}}-{{V}_{A}}=8\times {{i}_{2}}-4\times {{i}_{1}}\]                 \[=8\times \frac{10}{14}-4\times \frac{10}{7}=0\]