To find the efficiency of a light bulb, you can use the following formula for efficiency:
\[ \text{Efficiency} = \frac{\text{Useful Output Energy}}{\text{Input Energy}} \times 100% \]
In this case:
- Useful Output Energy (light energy output) = 10 J
- Input Energy (electrical energy input) = 100 J
Plugging these values into the formula:
\[ \text{Efficiency} = \frac{10, \text{J}}{100, \text{J}} \times 100% \]
Calculating this gives:
\[ \text{Efficiency} = 0.1 \times 100% = 10% \]
Thus, the efficiency of the light bulb is 10%.