Why Kaysons ?

Video lectures

Access over 500+ hours of video lectures 24*7, covering complete syllabus for JEE preparation.

Online Support

Practice over 30000+ questions starting from basic level to JEE advance level.

Live Doubt Clearing Session

Ask your doubts live everyday Join our live doubt clearing session conducted by our experts.

National Mock Tests

Give tests to analyze your progress and evaluate where you stand in terms of your JEE preparation.

Organized Learning

Proper planning to complete syllabus is the key to get a decent rank in JEE.

Test Series/Daily assignments

Give tests to analyze your progress and evaluate where you stand in terms of your JEE preparation.



  • 1
  • 2
  • 3
  • 4


When light is incident on a diffraction grating, the zero order principal maximum will be


The diffraction effect can be observed in


When a compact disc is illuminated by small source of white light, coloured bands are observed. This, is due to


Yellow light is used in single slit diffraction experiment with slit width 0.6 mm. If yellow light is replaced by X-rays, then the pattern will reveal that

Q. A thin film of soap solution (n = 1.4) lies on the top of a glass plate (n = 1.5). When visible light is incident almost normal to the plate, two adjacent reflection maxima are observed at two wavelength 400 and 630 nm. The minimum thickness of the soap solution is?

For reflection at the air-soap solution interface, the phase difference is π
For reflection at the interface of soap solution to glass also, there will be a phase difference of π.
∴ The condition for the maximum intensity
For n, nλ1​=(n−1)λ2​
This is the maximum order, where they coincide

Q. Maximum diffraction takes place in a given alit for?

Greater is the wavelength of wave higher will be its degree of diffraction.
Radio waves have maximum wavelength.

Q. Gamma is also an electromagnetic wave like light than why not gamma generates a plane wavefront??

When the point source or linear source of light is at very large distance, a small portion of spherical or cylindrical wavefront appears to be plane, such a wavefront is called a plane wavefront.
In the given options none of sources generates plane wavefront, it can be artificially produced by reflection from a mirror or by refraction through a lens.