When a p-n junction diode is subjected to a FORWARD BIAS (p-side connected to the positive terminal of the battery, n-side to the negative), the width of the depletion region

1. The depletion region's width is set by the balance between diffusion of carriers across the junction and the internal electric field of the fixed ions. 2. Forward biasing applies an EXTERNAL voltage that OPPOSES the internal junction field. The effective field decreases. 3. With a weaker barrier, more carriers can diffuse across; the boundary between fixed ions and mobile carriers shrinks back — DEPLETION WIDTH DECREASES. 4. Once the forward bias exceeds the BARRIER POTENTIAL (about $0.7\,\text{V}$ for Si, $0.3\,\text{V}$ for Ge), substantial current flows. 5. In REVERSE bias (option A's case), the external voltage adds to the internal field, sweeping more carriers away and INCREASING the depletion width. 6. Options B and D contradict the physics of bias. _Source: NCERT Class 12 Physics Part 2, Ch 14, §14.6.1 (p-n junction diode under forward bias), p. 11–12._