Question

A full wave rectifier circuit along with the input and output are shown in the figure. The contribution from the diode 1 is (are)-


A. C
B. A, C
C. B and D
D. A, B, C, D

Answer 1

Hint: The circuits that convert the AC (alternating current) to DC (direct current) are known as rectifiers. If both the positive and the negative half cycles of an input alternating waveform are rectified, these rectifiers are called full wave rectifiers.

Complete step by step answer:
Its working principle is-
The input transformer has an AC voltage. Terminal 1 will be positive, centre-tap potential will be zero and terminal 2 will be negative potentials for the positive half-cycle of the AC voltage. This causes the diode D1 to be biased and the flow of current. During this period, diode D2 is reverse biased and blocks the current.
Terminal 2 will be positive with respect to terminal 1 and centre-tap during the negative half-cycle of the input AC voltage. This will cause bias in diode D2 and the flow of current. During this time, the D1 diode is reverse biased and blocks the current through it.
The positive cycle is conducted by diode D1 and the negative cycle conducted by diode D2 which is during the positive cycle. Consequently, it is possible to pass through both half cycles. The average DC voltage output here is nearly 2 times that of a half-wave rectifier's DC output voltage.
Now, we are supposed to tell which wave we receive from diode D1. From the diagram, we can clearly see that wave A and wave C are received from diode D1.
Hence, option B is considered as the correct option.

Note: A significant amount of power is wasted when we use a half-wave rectifier, as the only half of each cycle passes through and the rest of the cycle is blocked. Furthermore, the half-wave rectifier (40.6%) cannot be used for applications that require smooth and steady DC output. We use a full wave rectifier for a more efficient and steadier DC.