Question

Aryan and Mira are playing with soap bubbles in sunlight. Aryan notices that the bubble appears purple, which is unusual. A scientist explains the phenomenon and gives the following statements:
I. The colour is due to interference of light in a thin film.
II. As the bubble thickness increases, the reflected colour shifts towards higher wavelength.
III. Purple colour appears because shorter wavelengths undergo constructive interference first.
IV. The colour is due to absorption of light by soap.
Which of the above statements correctly explain the observation?

• A. I and II only
• B. I, II and III only
• C. II and IV only
• D. I and IV only

Hint:

In physics multiple-choice questions, be wary of statements that provide an incorrect causal link ("A happens because of B," where B is true but doesn't cause A).
While it's true that shorter wavelengths interfere first, this fact doesn't explain the appearance of a composite color like purple. Stick to the fundamental and undisputed principles.

Answer 1

The Correct Option is A