Question: 2 A full wave rectifier circuit consists of two p-n junction diodes, a centre-tapped transformer, capacitor and a load resistance. Which of these components remove the ac ripple from the rectified output?
(1) Capacitor
(2) Load resistance
(3) A centre-tapped transformer
(4) p-n junction diodes
Answer: Option (1)
Explanation:
In a full wave rectifier, the output obtained after rectification is a pulsating dc which still contains ac ripples.
A capacitor connected across the load acts as a filter. It charges during the peak value of the rectified voltage and discharges slowly when the voltage falls.
This charging and discharging action smoothens the output voltage and reduces the ac ripple present in the rectified signal.
The p-n junction diodes only convert ac into pulsating dc, the centre-tapped transformer provides proper voltage and phase, and the load resistance does not remove ripples.
Therefore, the component that removes ac ripple from the rectified output is the capacitor.