Express the power of a 100 wtt bulb in CGS unit.

Explanation

To express the power of a 100-watt bulb in CGS units, we need to follow these steps:

### Step-by-Step Solution:

1. **Understand the Given Power**:
- The power of the bulb is given as 100 watts (W).
- By definition, 1 watt is equal to 1 joule per second (J/s).

2. **Convert Watts to Joules**:
- Since 100 watts means 100 joules of energy is used in 1 second, we can express this as:
\[ P = 100 \, \text{W} = 100 \, \text{J/s} \]

3. **Convert Joules to CGS Units**:
- In CGS (centimeter-gram-second) units, energy is measured in ergs.
- The conversion factor is:
\[ 1 \, \text{joule} = 10^7 \, \text{ergs} \]

4. **Calculate the Power in CGS Units**:
- To convert the power from joules to ergs, we multiply the power in joules by the conversion factor:
\[ P = 100 \, \text{J/s} \times 10^7 \, \text{ergs/J} \]
- This gives:
\[ P = 100 \times 10^7 \, \text{ergs/s} = 10^9 \, \text{ergs/s} \]

5. **Final Answer**:
- Therefore, the power of the 100-watt bulb in CGS units is:
\[ P = 10^9 \, \text{ergs/s} \]