How many diodes are used in a half-wave rectifier?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → One
A half-wave rectifier uses a single diode in series with the load. The diode conducts only in the half cycles of the ac input in which it is forward biased. So the output appears for only half of the input wave.
NCERT (2026-27):
Application of Junction Diode as a Rectifier – “If an alternating voltage is applied across a diode in series with a load, a pulsating voltage will appear across the load only during the half cycles of the ac input during which the diode is forward biased. Such rectifier circuit, as shown in Fig. 14.18, is called a half-wave rectifier.”
Fig. 14.18: (a) Half-wave rectifier circuit, (b) Input ac voltage and output voltage waveforms from the rectifier circuit.