question_answer

Directions for: The questions consist of two statements each, printed as assertion and reason. While answering these questions you are required to choose any one of the following five responses A. If both the Assertion and the Reason are true and the Reason is a correct explanation of the Assertion. B. If both the Assertion and the Reason are true but the Reason is not a correct explanation of Assertion. C. If the Assertion is true but the Reason is false. D. If both the Assertion and the Reason are false. E. If Assertion is false but Reason is true.

Assertion: Thin films such as soap bubble or a thin layer of oil on water show beautiful colours when illuminated by white light. Reason: It happens due to the interference of light reflected from the upper surface of the thin film.

A)  A        

B)                        B                           

C)        C                                           

D)  D            

E)  E

Correct Answer: C

Solution :

When a thin film of oil spread over the surface of water is seen in broad-day light, brilliant colours are seen--in the film. A similar colour pattern is seen in soap bubbles. These colours arise due to interference of sun-light reflected from the upper and lower surfaces of the film.