NEET Physics Question (2026) — Solution

Step-by-step solution

From the given circuit diagram, we can determine the biasing of each diode by observing their connections to the battery. The battery symbol has its longer line on the left and shorter, thicker line on the right. This indicates that the left side of the circuit is connected to the positive terminal and the right side to the negative terminal. 1. For diode D_1: The p-side (triangle) is connected to the positive terminal (via a resistor) and the n-side (straight line) is connected to the negative terminal. Thus, D_1 is forward-biased. 2. For diode D_2: The p-side is connected to the positive terminal, but there is a clear break in the circuit on its n-side. Since it is an open circuit, no current flows through it, meaning D_2 is unbiased. 3. For diode D_3: The n-side is connected to the positive terminal and the p-side is connected to the negative terminal (via a resistor). Thus, D_3 is reverse-biased. The width of the depletion region of a p-n junction depends on its biasing: - In forward bias, the applied voltage opposes the built-in potential, causing the depletion width to decrease. - In an unbiased state, the depletion width remains at its natural equilibrium value. - In reverse bias, the applied voltage adds to the built-in potential, causing the depletion width to increase. Let W_ eq be the equilibrium depletion width. Based on the biasing, we have: W_1 W_2 = W_ eq (unbiased) W_3 > W_ eq (reverse-biased) Comparing these widths, we get the relation: W_3 > W_2 > W_1 Answer: W_3>W_2>W_1