In a carbon resistor the last band colour is missing. Its tolerance is

Options

A. `5%`
B. `10%`
C. `20%`
D. `0%`

Answer

To determine the tolerance of a carbon resistor when the last band color is missing, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Resistor Color Code**:
- A carbon resistor typically has four color bands. The first three bands indicate the resistance value, while the fourth band indicates the tolerance of the resistor.

2. **Identifying the Role of the Fourth Band**:
- The fourth band is crucial as it tells us how much the actual resistance can vary from the stated value.

3. **Tolerance Values Based on Color**:
- If the fourth band is:
- Gold: ±5% tolerance
- Silver: ±10% tolerance
- No color: ±20% tolerance

4. **Analyzing the Given Information**:
- In this case, the last band color is missing. This means we need to refer to the tolerance values when the last band is absent.

5. **Conclusion**:
- Since the last band is missing, the tolerance of the carbon resistor is ±20%.

### Final Answer:
The tolerance of the carbon resistor with the last band color missing is ±20%.

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