Colours of thin soap bubbles are due to

Options

A. refraction
B. dispersion
C. interference
D. diffractions

Answer

**Step-by-Step Solution:**

1. **Understanding the Structure of Soap Bubbles:**
- A soap bubble consists of two surfaces: an upper surface and a lower surface.

2. **Incident Light on the Bubble:**
- When white light (which contains all colors) strikes the soap bubble, it interacts with both surfaces of the bubble.

3. **Reflection of Light:**
- The light is partly reflected by the upper surface of the bubble and partly by the lower surface. This creates two sets of reflected light waves.

4. **Superposition of Reflected Light Waves:**
- The two reflected light waves from the upper and lower surfaces combine or superpose when they emerge from the bubble.

5. **Interference of Light Waves:**
- The superposition of these two reflected light waves leads to interference. Depending on the path difference between the two waves, certain colors will constructively interfere (resulting in bright colors) while others will destructively interfere (resulting in dim or no colors).

6. **Condition for Maxima:**
- The colors that are visible in the reflected light correspond to the wavelengths that satisfy the condition for constructive interference (maxima).

7. **Conclusion:**
- Therefore, the colors observed in thin soap bubbles are due to the phenomenon of interference of light waves reflected from the two surfaces of the bubble.

**Final Answer:**
The colors of thin soap bubbles are due to interference.

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