MHT CET2016PhysicsWave Optics
Two coherent sources P and Q produce interference at point A on the screen where there is a dark band which is formed between 4 t h bright band and 5 t h bright band. Wavelength of light used is 6000 Å . The difference between P A and Q A is
Options
- A1.4 × 10 - 4 c m
- B2.7 × 10 - 4 c m
- C4.5 × 10 - 4 c m
- D6.2 × 10 - 4 c m
Correct answer
B. 2.7 × 10 - 4 c m
Step-by-step solution
Here ∆ x = λ δ 2 π For n = 4 t h dark b and δ = 2 n + 1 π ⇒ δ = 8 + 1 π = 9 π ∆ x = λ . 9 π 2π = 9 2 × λ = 9 2 × 6 × 10 - 7 = 2.7 × 10 - 6 m = 2.7 × 10 - 4 c m