Question

Consider a Young's double slit experiment as shown in figure. What should be the slit separation d in terms of wavelength $\lambda$ such that the first minima occurs directly in front of the slit $(S_1)$ ?

• A. $\frac{\lambda }{2\left(5-\sqrt{2}\right)}$
• B. $\frac{\lambda }{\left(5-\sqrt{2}\right)}$
• C. $\frac{\lambda }{\left(\sqrt{5}-2\right)}$
• D. $\frac{\lambda }{2\left(\sqrt{5}-2\right)}$

Answer 1

Answer: (D)

$\sqrt{5}d-2d=\frac{\lambda }{2}$