Q. Which of the following appear to display different colours primarily due to the phenomenon of interference?

1. Soap bubble
2. Rainbow
3. Oil slick on wet road

Select the correct option from the codes given below:
Answer: Only 1 & 3
Notes: Soap bubbles and oil slicks exhibit colours due to thin film interference, where light reflects from upper and lower surfaces and undergoes constructive or destructive interference. Rainbows, however, result from dispersion, reflection, and refraction of light in water droplets, not from interference. Thus, only soap bubbles and oil slicks are caused by interference.