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:

### Related Formula textAngular fringe width theta = fraclambdad$$\text{Angular fringe width } \theta = \frac{\lambda}{d}$$ ### Core Logic The angular separation (angular fringe width) theta$\theta$ is given by fraclambdad$\frac{\lambda}{d}$, where lambda$\lambda$ is the wavelength and d$d$ is the separation between slits. It is completely independent of the distance to the screen D$D$. Statement I claims moving the screen away (increasing D$D$) increases angular separation. Since theta$\theta$ doesn't depend on D$D$, Statement I is false. Statement II claims using a higher wavelength lambda$\lambda$ increases angular separation. Since theta propto lambda$\theta \propto \lambda$, increasing lambda$\lambda$ increases theta$\theta$. Statement II is true. ### Step 1: Final Conclusion Statement I is false but Statement II is true. ### Pattern Recognition Linear fringe width y = lambda D / d$y = \lambda D / d$ depends on D$D$, but angular fringe width theta = lambda / d$\theta = \lambda / d$ isolates only the slit separation and wavelength. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 12 Physics: Wave Optics