Which of the following statements is true ?

Options

A. The image formed by a pinhole camera is inverted because light travels in a straight line.
B. Light does not change its direction on reflection.
C. As we move the object away from the light source, the shadow of the object becomes smaller
D. Reflection is possible only from polished surface.

Explanation

To determine which of the given statements is true, let's analyze each statement one by one:

### Step 1: Analyze Statement 1
**Statement 1:** "The image formed by a pinhole camera is inverted because light travels in a straight line."

- A pinhole camera works by allowing light to enter through a small hole (the pinhole) and project an image on the opposite side. The image is inverted due to the geometry of light paths.
- While it is true that light travels in a straight line, the reason the image is inverted is not solely because of this property. The inversion occurs because the light rays cross at the pinhole.
- **Conclusion:** This statement is **false**.

### Step 2: Analyze Statement 2
**Statement 2:** "Light does not change its direction on reflection."

- When light reflects off a surface, it changes direction according to the law of reflection (the angle of incidence equals the angle of reflection).
- Therefore, this statement is incorrect because light does indeed change its direction when it reflects.
- **Conclusion:** This statement is **false**.

### Step 3: Analyze Statement 3
**Statement 3:** "As we move the object away from the light source, the shadow of the object becomes smaller."

- When an object is moved away from a light source, the shadow it casts on a surface does indeed become smaller. This is because the light rays diverge as they travel away from the source, and the object blocks less light as it moves further away.
- **Conclusion:** This statement is **true**.

### Step 4: Analyze Statement 4
**Statement 4:** "Reflection is possible only from polished surfaces."

- Reflection can occur on both polished and rough surfaces. While polished surfaces produce clear reflections (specular reflection), rough surfaces also reflect light (diffuse reflection), albeit in a scattered manner.
- Therefore, this statement is incorrect.
- **Conclusion:** This statement is **false**.

### Final Conclusion
After analyzing all four statements, we find that **Statement 3** is the only true statement: "As we move the object away from the light source, the shadow of the object becomes smaller."

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