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. The reverse current remains small ( μ A ) until the reverse bias reaches the breakdown voltage ( Vbr ), where it increases sharply due to junction breakdown. Substituting values gives Breakdown voltage, which matches expected behaviour for this semiconductor device configuration, confirming doping, depletion and rectifier principles.