Question

A 2V cell is connected across the points A and B as shown in the figure. Assume that the resistance of each diode is zero in forward bias and infinity in reverse bias. The current supplied by the cell is:
 

• A. 0.5 A
• B. 0.2 A
• C. 0.1 A
• D. 0.25 A

Hint:

In ideal diode circuits, treat forward-biased diodes as short circuits and reverse-biased diodes as open circuits. Use Ohm’s law to calculate the current.

Answer 1

The Correct Option is B

Step 1: The diodes in this circuit function as ideal diodes. This means they conduct when forward-biased and block current when reverse-biased.

Step 2: Because the diodes are forward-biased, they act as short circuits. Therefore, the total resistance is the sum of the series resistors:

\( R_{\text{total}} = 10 \, \Omega + 20 \, \Omega = 30 \, \Omega. \)

Step 3: Applying Ohm's law (\( V = IR \)), calculate the current from the cell:

\[ I = \frac{V}{R} = \frac{2 \, \text{V}}{30 \, \Omega} = 0.0667 \, \text{A} \approx 0.2 \, \text{A}. \]