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 follow these steps:

### Step 1: Understand the given power in SI units
The power of the bulb is given as 100 watts. In SI units, power (P) is defined as:
\[ P = 1 \text{ watt} = 1 \text{ joule/second} \]

### Step 2: Convert watts to joules per second
Since 1 watt is equal to 1 joule per second, we can express 100 watts as:
\[ 100 \text{ watts} = 100 \text{ joules/second} \]

### Step 3: Convert joules to ergs
In the CGS unit system, energy is measured in ergs. The conversion factor between joules and ergs is:
\[ 1 \text{ joule} = 10^7 \text{ ergs} \]

### Step 4: Substitute the conversion factor
Now, we can convert 100 joules into ergs:
\[ 100 \text{ joules} = 100 \times 10^7 \text{ ergs} \]
This gives us:
\[ 100 \text{ joules} = 10^9 \text{ ergs} \]

### Step 5: Write the power in CGS units
Since power is energy per time, we can express the power in CGS units as:
\[ P = \frac{10^9 \text{ ergs}}{1 \text{ second}} \]
Thus, the power of the bulb in CGS units is:
\[ P = 10^9 \text{ ergs/second} \]

### Final Answer
The power of a 100-watt bulb in CGS units is:
\[ \boxed{10^9 \text{ ergs/second}} \]

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