# General Knowledge - Physics - Discussion

### Discussion :: Physics - Section 1 (Q.No.26)

26.

On a rainy day, small oil films on water show brilliant colours. This is due to

 [A]. dispersion [B]. interference [C]. diffraction [D]. polarization

Explanation:

No answer description available for this question.

 Pallavi said: (Aug 11, 2011) What is actual process of interference?

 Anjali said: (Oct 27, 2011) Interference is the phenomenon in which two waves superpose each other to form a resultant wave of greater or lower amplitude.

 Tannistha said: (Nov 26, 2011) Please make an elaborate explanation.

 Dibakar Bauri said: (Jan 24, 2012) Interference : When two different waves having different velocities are overlap with each other and produce a new one it is called Interference. In the case of rain water it happens.

 Pradeebha.T said: (Feb 6, 2012) Water having lightly packed molecules. So the oil spread easily on the water.

 Surya said: (Feb 29, 2012) This is not only on rainy day if we threw oil films on water in light there also we can observe interference pattern.

 Prof. Sunita Dandwate said: (Jun 25, 2012) Due to oil, a thin film is formed on water surface. When light falls upon it, then it undergo multiple reflections at its top and bottom layers. Interference takes place between these reflected rays. Now depending upon the angle of incidence/reflection, thickness of the oil film, viewing angle etc., different colors are produced on the film.

 Namya Gupta said: (Oct 17, 2012) The different waves coming from sun falls on water and starts coming in a same phase.

 Ravi said: (Jul 26, 2013) It has to be due prism like formation. Where the white light splits into various colors the effect of interference could be to the extent of making these colors bright. So both diffraction n interference could be responsible.

 Arshil said: (Dec 11, 2013) On the surfaces of water thin layer of oil produced partial refraction and reflection, the refracted light will also reflected from the water surface, due to theses reflected non monochromatic rays interference is occurred.

 Navi said: (Sep 18, 2014) Oil spreads in water interference takes place.

 Shru said: (Jan 8, 2015) Can give other example for interference?

 Seema Singh said: (Mar 24, 2015) Why should not dispersion be the correct answer?

 Sasi Sri said: (May 28, 2015) @Shru. Interference effects can be observed with all types of waves, for example, light, radio, acoustic, surface water waves or matter waves.

 Anshu said: (Jul 16, 2015) How can two superimposing waves generate different colours?

 Balaji said: (Oct 1, 2015) Interference: It is due to the super position of the secondary wavelets from two different wave fronts produced by two coherent sources.

 Dhruv said: (Dec 12, 2015) What is polarization?

 Kennyjam said: (Aug 1, 2016) I doubt this ''interference'' as the answer. It should be Dispersion. The oil film acts as a medium which separates white lght into different components, due to the different speed rates of white light components.

 Baseerat said: (Nov 17, 2016) I am confused. I think this is due to Dispersion, not interference. Interference pattern consists of white and dark fringes, not on different color like a rainbow. Would someone can clear my confusion?

 Apiku Richard said: (Apr 28, 2017) The correct answer is dispersion. The oil forms a thin layer on the surface of the wet ground. This layer dispersed the light entering the thin oil layer. This dispersed light is totally internally reflected in the oil.

 Onwuanibe Ruth said: (May 11, 2017) I still need to understand the meaning of both interference and dispersion. So please would someone be of help?