Question

To increase the angular width of interference fringes

• A. wavelength should increase
• B. distance between coherent sources should increase
• C. either (a) or (b)
• D. neither (a) nor (b)

Answer 1

Answer: (A)

wavelength should increase

Answer 2

Angular fringe width is given by $\beta = \frac{\lambda}{d} .$Angular fringe width increases when wavelength increases and distance between coherent sources decreases.