An alternating current can be converted into direct current by a

Options

A. rectifier
B. dynamo
C. transformer
D. motor

Answer

To solve the question, "An alternating current can be converted into direct current by a," we need to identify the process or device that performs this conversion.

### Step-by-Step Solution:

1. **Understanding Alternating Current (AC)**:
- Alternating current is an electric current that reverses its direction periodically. It is characterized by its sinusoidal waveform.

2. **Understanding Direct Current (DC)**:
- Direct current is an electric current that flows in one direction only. It is characterized by a constant voltage or current.

3. **Identifying the Conversion Process**:
- The process of converting AC to DC is known as rectification.

4. **Rectifiers**:
- A rectifier is a device that converts alternating current (AC) into direct current (DC). There are two main types of rectifiers:
- **Half-Wave Rectifier**: This type of rectifier only allows one half of the AC waveform to pass through, effectively blocking the other half. It produces a series of positive pulses.
- **Full-Wave Rectifier**: This type allows both halves of the AC waveform to be utilized, producing a smoother DC output.

5. **Conclusion**:
- Therefore, the answer to the question is that an alternating current can be converted into direct current by a **rectifier**.

### Final Answer:
An alternating current can be converted into direct current by a **rectifier**.