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 :

We analyze both statements about Young's double slit experiment.

Statement I: The angular separation of fringes will increase as the screen is moved away from the plane of the slits.

The angular fringe separation is given by $$\Delta\theta = \frac{\lambda}{d}$$, where $$\lambda$$ is the wavelength and $$d$$ is the slit separation.

This expression is independent of the distance $$D$$ between the slits and the screen. Therefore, moving the screen away does not change the angular separation.

Statement I is false.

Statement II: The angular separation of fringes will increase when the monochromatic source is replaced by another monochromatic source of higher wavelength.

Since $$\Delta\theta = \frac{\lambda}{d}$$, increasing $$\lambda$$ increases $$\Delta\theta$$.

Statement II is true.

Therefore, Statement I is false but Statement II is true.

The correct answer is Option B.