Easy MCQ +4 / -1 PYQ · JEE Mains 2021

If the source of light used in a Young's double slit experiment is changed from red to violet :

  1. A the fringes will become brighter.
  2. B the intensity of minima will increase.
  3. C consecutive fringe lines will come closer. Correct answer
  4. D the central bright fringe will become a dark fringe.

Solution

According to Young's double slit experiment, the distance of nth bright fringe from the centre,<br/><br/>${y_n} = {{n\lambda D} \over d}$<br/><br/>Since, ${\lambda _{violet}} < {\lambda _{red}}$<br/><br/>$\therefore$ ${y_{violet}} < {y_{red}}$<br/><br/>$\therefore$ Consecutive fringe lines will come closer.

About this question

Subject: Physics · Chapter: Optics · Topic: Reflection and Mirrors

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