Candela is the unit of

Options

A. acoustic intensity
B. electric intensity
C. luminous intensity
D. magnetic intensity.

Answer

To solve the question "Candela is the unit of:", we need to identify what the term "candela" refers to in the context of physical measurements.

### Step-by-Step Solution:

1. **Understanding the Term "Candela":**
- The term "candela" is derived from the Latin word for "candle." This gives us a clue that it is related to light.

2. **Identifying the Context:**
- In physics, units are used to measure various quantities. We need to determine which physical quantity candela is associated with.

3. **Analyzing the Options:**
- The options provided are:
- Acoustic intensity
- Electrical intensity
- Luminous intensity
- Magnetic intensity
- We need to evaluate each option to see which one is related to light.

4. **Evaluating Each Option:**
- **Acoustic Intensity:** This refers to sound intensity, which is not related to light.
- **Electrical Intensity:** This pertains to electric current or voltage, which again is not related to light.
- **Luminous Intensity:** This is a measure of the perceived power of light. It directly relates to how much light is emitted from a source in a particular direction.
- **Magnetic Intensity:** This relates to magnetic fields and is not associated with light.

5. **Conclusion:**
- Since "luminous intensity" is the only option that relates to light, we conclude that candela is the unit of luminous intensity.

### Final Answer:
**Candela is the unit of luminous intensity.**