The diode in a half-wave rectifier conducts during:
**Rectifier applications** diode must have reverse breakdown voltage higher than peak inverse voltage, centre-tap transformer provides two opposite phase voltages for full-wave, capacitor discharges through load R_L when diode off, drift current in junction is minority carrier motion due to field, diffusion due to gradient, diode conducts when forward biased anode positive. In a half-wave rectifier, the diode is forward biased and conducts only during the positive half-cycle of the AC input, blocking the negative half-cycle. Substituting values gives Positive half-cycle, which matches expected
Ref: NCERT > Physics Book > Electronic Devices > Rectifiers, Filters and Applications