Practice question

**Diode characteristics** forward bias reduces barrier, width of depletion region decreases, resistance low ~10-100 Ω, current primarily due to majority diffusion, exponential I = I_s(e^{eV/kT}-1), reverse bias widens depletion region, resistance high ~MΩ, dominant current drift due to minority carriers, reverse saturation current small μA-nA, typically 10⁻⁶ A, increases sharply at breakdown Zener/avalanche. In forward bias, the applied voltage ( V ) opposes the built-in potential ( V₀ ), reducing the effective barrier height to V₀ - V , allowing more carriers to cross the junction. Substituting values gives V₀ - V, which matches expected behaviour for this semiconductor device configuration, confirming doping, depletion and rectifier principles.