Hot wire ammeters are used for measuring

Options

A. Both AC and DC
B. Only AC
C. Only DC
D. Neither AC nor DC

Answer

To solve the question regarding what hot wire ammeters are used for measuring, we can break down the information provided in the video transcript into a structured solution.

### Step-by-Step Solution:

1. **Understanding Hot Wire Ammeters**:
- Hot wire ammeters are devices that measure electric current based on the principle of thermal expansion. They consist of a thin wire that heats up when an electric current passes through it.

2. **Principle of Operation**:
- The operation of hot wire ammeters is based on the heating effect of current. When current flows through the wire, it generates heat due to its resistance. The amount of heat generated is proportional to the square of the current (I²R), where I is the current and R is the resistance.

3. **AC and DC Current**:
- AC (Alternating Current) and DC (Direct Current) are two types of electric current. AC changes direction periodically, while DC flows in one direction.

4. **Effect of Current Type on Measurement**:
- Since the heat generated in the wire is proportional to the square of the current, the sign of the current does not affect the heating effect. This means that whether the current is AC or DC, the hot wire ammeter will still measure the current effectively.

5. **Conclusion**:
- Based on the principles of thermal expansion and the heating effect of current, hot wire ammeters can measure both AC and DC currents.

### Final Answer:
Hot wire ammeters are used for measuring both AC and DC.

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