Question

In a Young’s double slit experiment, wavelength of light used is ?. Let O be the centre of line joining the slits and C be the centre of screen where interference pattern is being obtained. ? is the angular position of each slit with respect to C and ? is the angular position of first maxima with respect to O. select the correct option(s).

• A. Fringe width obtained is $\frac{\lambda \theta }{2}$
• B. Fringe width obtained is $\frac{\lambda }{2\theta }$
• C. The distance between the slits is $\frac{\lambda }{\varphi }$
• D. The distance between the slits and screen is $\frac{\lambda }{2\varphi \theta }$

Answer 1

Answer: (B), (C), (D)

The correct options are
B Fringe width obtained is $\frac{\lambda }{2\theta }$
C The distance between the slits is $\frac{\lambda }{\varphi }$
D The distance between the slits and screen is $\frac{\lambda }{2\varphi \theta }$


$\omega =\frac{D\lambda }{d}=D\varphi$ and $\frac{d}{2}=D\theta$
$\therefore \omega =\frac{\lambda }{2\theta },d=\frac{\lambda }{\varphi }$ and $D=\frac{d}{2\theta }=\frac{\lambda }{2\varphi \theta }$