Why clear streams appear shallow ?

Explanation

### Step-by-Step Solution:

1. **Understanding Refraction**:
- Refraction is the bending of light as it passes from one medium to another. This occurs due to a change in the speed of light in different media.
- When light travels from a rarer medium (like air) to a denser medium (like water), it bends towards the normal line. Conversely, when it travels from a denser medium to a rarer medium, it bends away from the normal.

2. **Analyzing the Situation**:
- In the case of a clear stream, the water acts as a denser medium compared to the air above it.
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