Given below are two statements : Statement I: In a Young's double slit experiment, the angular separ

Question

Given below are two statements : Statement I: In a Young's double slit experiment, the angular separation of fringes will increase as the screen is moved away from the plane of the slits Statement II: In a Young's double slit experiment, the angular separation of fringes will increase when monochromatic source is replaced by another monochromatic source of higher wavelength In the light of the above statements, choose the correct answer from the options given below :

Professor PC Thomas Classes · Answer

The angular separation between fringes in YDSE is $	heta = \frac{\lambda}{d}$. It is independent of the distance $D$ between the slits and the screen. Hence, Statement I is false. Since $	heta \propto \lambda$, replacing the source with one of a higher wavelength increases the angular separation. Hence, Statement II is true.