For Young’s double-slit experiment, Statement I: If the screen is moved away from the plane of slits, angular separation of fringes remains constant. Statement II: If the monochromatic source is replaced by another monochromatic source of larger wavelength, angular separation of fringes decreases. Choose the correct answer.
Options

Question

For Young’s double-slit experiment, Statement I: If the screen is moved away from the plane of slits, angular separation of fringes remains constant. Statement II: If the monochromatic source is replaced by another monochromatic source of larger wavelength, angular separation of fringes decreases. Choose the correct answer.

Options

G1 Physics · Accepted Answer

Step 1: Fringe separation β = λD/d. Angular fringe width ≈ β/D = λ/d. Step 2: This does not depend on screen distance D: Statement I is true. Step 3: Increasing λ increases λ/d, not decreases it: Statement II is false. Final answer: (A).