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Wave Optics — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsWave Optics1 Mark
Question
For question two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.
  1. Both A and R are true and R is the correct explanation of A.
  2. Both A and R are true but R is NOT the correct explanation of A.
  3. A is true but R is false.
  4. A is false and R is also false.
Assertion (A): In interference all the fringes are of same width.
Reason (R): In interference fringe width is independent of position of the fringe.
✓

Answer

  1. Both A and R are true and R is the correct explanation of A.

Explanation:

As given in the expression $\beta=\frac{\text{D}\lambda}{\text{d}}$, fringe width $\beta$ is independent of n (position of fringe), hence all the fringes are of same width.

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