Question

In the figure, the potential difference between A and B is:

• A. 0 V
• B. 2 V
• C. 4 V
• D. 8 V

Hint:

To calculate potential differences in circuits with resistors and diodes, remember to use Ohm’s law to find the current and then determine the voltage drops across resistors.

Answer 1

The Correct Option is C

The circuit shown consists of resistors and a diode. To find the potential difference between points A and B, we first analyze the circuit behavior. Since the diode is forward biased (due to the potential difference from the 24V battery), it will conduct. The resistors \( R_1 \) and \( R_2 \) are in series, with a total resistance of: \[ R_{\text{total}} = R_1 + R_2 = 8\,k\Omega + 8\,k\Omega = 16\,k\Omega \] The total current \( I \) through the circuit can be found using Ohm’s law: \[ I = \frac{V}{R_{\text{total}}} = \frac{24\,V}{16\,k\Omega} = 1.5\,mA \] Now, the potential drop across \( R_2 \) (which is the same as \( R_1 \)) is: \[ V_{R_2} = I \times R_2 = 1.5\,mA \times 8\,k\Omega = 12\,V \] The remaining potential drop across \( R_1 \) (which corresponds to the potential difference between A and B) is: \[ V_{\text{AB}} = V - V_{R_2} = 24\,V - 12\,V = 4\,V \] Thus, the potential difference between points A and B is 4V.