Based on the understanding operations of rectifies answer the questions Diodes can be used for rectifying on ac voltage (restricting the ac voltage to one direction) with the help of a capacitor or a suitable filter, a dc voltage ca be obtained.
Capacitor is used in the rectifier circuit because :
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → It eliminates ripples/Fluctuations and gives almost constant DC voltage output across the
The output of a rectifier is pulsating dc: it has one sign but rises and falls. A capacitor connected across the load acts as a filter.
While the rectified voltage rises, the capacitor charges up to the peak value. When the rectified voltage falls, the diode stops conducting and the capacitor discharges slowly through the load \( R_L \), keeping the voltage across it high until the next pulse arrives. The gaps between the pulses are filled, so the ripple is removed and the output is an almost steady dc voltage.
NCERT (2026-27):
Application of Junction Diode as a Rectifier – “… To get steady dc output from the pulsating voltage normally a capacitor is connected across the output terminals (parallel to the load RL). … Since these additional circuits appear to filter out the ac ripple and give a pure dc voltage, so they are called filters. … The output voltage obtained by using capacitor input filter is nearer to the peak voltage of the rectified voltage.”