Question

Potential difference across $AB$ shown in the figure is:

• A. 10 V
• B. 12 V
• C. 8 V
• D. 0 V

Answer 1

Answer: (D)

• In the given figure, $A$ and $B$ are on the same potential as there is a direct connection between $A$ and $B$ without any other element (via $D$)

So $V_A=V_B$

Potential difference $=V_B-V_A=0$

• Alternatively,

we can see that

Voltage between $A$ and $C$ i.e. $V_{AC}=V_A-V_C=10V$ . . . (i)

And,

Voltage between $C$ and $B$ i.e.$V_{CB}=V_C-V_B=-10V$ . . . (ii)

Adding $\left(i\right)$ and $\left(ii\right)$,

$(V_A-V_C)+(V_C-V_B)=10+(-10)$

$\Rightarrow V_A-V_B=0$

So Voltage between $A$ and $B$ i.e.$V_{AB}=V_A-V_B=0V$

Thus, option D is correct.