Question

Select the correct statement:
A. In a full-wave rectifier, two diodes work alternatively
B. In a full-wave rectifier, two diodes work simultaneously
C. The efficiency of full and half rectifiers are the same
D. The full-wave rectifier is bi-directional

Answer 1

Find the working principle of a full-wave rectifier where the above four options are being mentioned. It has two methods of being created, one of them is mentioned in the options above. A full-wave rectifier is known as a rectifier that converts the whole cycle of alternating current into a pulsating DC.

Complete answer:
The circuit of the full-wave rectifier can be constructed in two ways. The first way is where a center-tapped transformer is used and two diodes. This way is known as a center-tapped full-wave rectifier. The second way is where a standard transformer is used with four diodes arranged as a bridge. This is known as a bridge rectifier. Its working can be known by the input AC supplied to the full-wave rectifier is very high. The anode of the center-tapped diodes is connected to the transformer’s secondary winding and it is also connected to the load resistor. During the first positive half cycle of the AC, the first half of the secondary winding becomes positive while the second half of the secondary winding becomes negative. During the positive half cycle, diode D1 is forward biased because it is connected to the top of the secondary winding, and diode D2 is reverse biased because it is connected below the secondary winding. Because of this, diode D1 will start acting as a short circuit and D2 will not start acting as an open circuit
When the negative half cycle occurs, the diode D1 is reverse biased and the diode D2 is forward biased because the first half of the secondary circuit becomes negative and the bottom half of the circuit becomes positive. Therefore for full-wave rectifiers, DC voltage is received for both positive and negative half-cycles.
Hence: In a full-wave rectifier, a rectifier circuit whose transformer secondary is tapped to get the desired output voltage using two diodes alternatively to rectify the complete cycle is called Centre tapped Full wave rectifier circuit (Option A) In a full-wave rectifier two diodes work alternatively.

Note: While this kind of method may be suitable for low-power applications, it is unsuitable to applications that need a steady and smoothed supply voltage. One way to improve on this is to use every half-cycle of the input voltage instead of every other half-cycle. This kind of method may apply to Full-wave rectifiers.