Question

In the figure, potential difference between $\text{A}$ and $\text{B}$ is:

• A. $\text{10 V}$
• B. $\text{5 V}$
• C. $\text{15 V}$
• D. Zero

Answer 1

The correct option is A $\text{10 V}$

In the given circuit, diode is in forward bias. So it will behave like a conducting wire.

Therefore, the two $10\text{k}\Omega$ resistances in parallel can be reduced to a single equivalent resistance of $5\text{k}\Omega$.


So, from potential distribution formula, potential difference between $\text{AB}$ will be

$V_A-V_B=V\times \frac{R_{AB}}{R_{total}}=30\times \frac{5}{15}$

$\Rightarrow V_A-V_B=10\text{V}$

Hence, option $\left(A\right)$ is correct.