The Single-Phase Full Wave Rectifier

The correct answer is option 'C': two pulse rectifier. In order to understand why, let's first discuss the concept of rectification and then explore the operation of a single-phase full wave rectifier.

Rectification:
Rectification is the process of converting an alternating current (AC) into a direct current (DC). This is commonly done using a rectifier, which consists of one or more diodes. Diodes are electronic components that allow current to flow in only one direction.

Single-Phase Full Wave Rectifier:
A single-phase full wave rectifier is a rectifier that utilizes four diodes to convert AC into DC. It is also known as a bridge rectifier or a Graetz circuit. The main advantage of this rectifier compared to a half-wave rectifier (which uses only two diodes) is that it provides a higher average output voltage and a smoother DC output.

Operation:
The operation of a single-phase full wave rectifier can be divided into four phases, as follows:

Phase 1: Positive Half-Cycle (Diodes D1 and D3 Conducting)
- During the positive half-cycle of the input AC voltage, the diodes D1 and D3 are forward-biased, while the diodes D2 and D4 are reverse-biased.
- As a result, the current flows through the load resistor in the direction from D1 to D3, and the output voltage across the load resistor is positive.

Phase 2: Negative Half-Cycle (Diodes D2 and D4 Conducting)
- During the negative half-cycle of the input AC voltage, the diodes D2 and D4 are forward-biased, while the diodes D1 and D3 are reverse-biased.
- Now, the current flows through the load resistor in the opposite direction, from D2 to D4, and the output voltage across the load resistor is negative.

Phase 3: Positive Half-Cycle (Diodes D1 and D3 Conducting)
- In this phase, the diodes D1 and D3 conduct again, allowing the current to flow from D1 to D3.
- However, since the input AC voltage is positive, the output voltage across the load resistor remains positive.

Phase 4: Negative Half-Cycle (Diodes D2 and D4 Conducting)
- Finally, during this phase, the diodes D2 and D4 conduct, causing the current to flow from D2 to D4.
- Similar to phase 2, the output voltage across the load resistor is negative.

Conclusion:
By analyzing the operation of a single-phase full wave rectifier, we can conclude that it produces two pulses of DC output during each cycle of the input AC voltage. Hence, the correct answer is option 'C': two pulse rectifier.