Physics Circle home Student Login

Home›Chapters›Wave Optics PYQs›YDSE: Fringe Width & Fringe Positions›Question 6

MHT CET 2026 (13 May, Shift 2) · YDSE: Fringe Width & Fringe Positions

YDSE: Fringe Width & Fringe Positions question from MHT CET 2026 (13 May, Shift 2)

Q6MHT CET 2026 · 13 MAY · SHIFT 2Easy

YDSE: Fringe Width & Fringe Positions

Two coherent sources PP and QQ produce interference at a point AA on the screen where there is a dark band which is formed between 44th bright band and 55th bright band. Wavelength of light used is 60006000 Å. The path difference between PAPA and QAQA is x×10−4x \times 10^{-4} cm. The value of xx is

Show answer and solution

Answer: (b)

  1. The dark band between the 4th and 5th bright bands is the 5th dark band.
  2. Path difference for nnth dark: (2n−1)λ2=4.5λ\frac{(2n-1)\lambda}{2} = 4.5\lambda
  3. 4.5×6000×10−8 cm=2.7×10−4 cm4.5 \times 6000\times10^{-8}\text{ cm} = 2.7\times10^{-4}\text{ cm}
  4. So the answer is (b) 2.72.7.
Report a mistake

More questions on YDSE: Fringe Width & Fringe Positions