How is the Light Intensity Varied?

Light intensity is varied primarily by adjusting the distance between the light source and the object receiving the light.

## Understanding Light Intensity and Distance

Based on the principles of light, **the light intensity is proportional to distance**. This means that the strength of the light decreases as you move further away from the source. As the reference states, "it will decrease as the distance away from the bulb increases".

Think of it like sound – the closer you are to a speaker, the louder it is; the further away, the quieter. Light behaves similarly.

## Varying Intensity by Changing Distance

The most direct way to vary light intensity, as described in the reference, is by physically altering the space between the light source (like a lamp or bulb) and the subject (like a plant in an investigation).

Therefore, **light intensity for the investigation can be varied by changing the distance from the lamp to the plant**.

### Practical Application:

*   **Increasing Intensity:** To make the light brighter on the subject, move the light source closer.
*   **Decreasing Intensity:** To make the light dimmer on the subject, move the light source further away.

This method is commonly used in experiments involving plants, photography, or any scenario where controlled light exposure is needed.

### The Relationship Illustrated

While the reference states intensity is proportional to distance (meaning they are related), it clarifies the *direction* of the relationship: intensity *decreases* as distance *increases*. This inverse relationship is key.

| Action                | Result on Distance | Result on Light Intensity |
| :-------------------- | :----------------- | :------------------------ |
| Move lamp *closer*    | Decreases          | Increases                 |
| Move lamp *further* | Increases          | Decreases                 |

By simply adjusting the physical distance, you can effectively control the amount of light energy falling on a surface or object.