Question

The Young's double slit experiment is performed with blue light and green light of wavelengths 4360 A${}^{\circ }$ and 5460 A${}^{\circ }$ respectively. If y is the distance of 4th maxima from the central one, then:

• A. $y_b=y_g$
• B. $y_b>y_g$
• C. $y_b<y_g$
• D. $\frac{y_b}{y_g}=\frac{5460}{4360}$

Answer 1

Answer: (C)

$y_b<y_g$

$4^{th}$ maxima is at:
$y=\frac{4D\lambda }{d}$
So, $y_g=\frac{4D\lambda g}{d}$------------(1)
and, $y_b=\frac{4D{\lambda }_b}{d}$----------(2)
Drviding 1 by 2,
$\frac{y_g}{y_a}=\frac{{\lambda }_g}{{\lambda }_b}$
$\frac{y_g}{y_b}=\frac{5460\dot{A}}{4360\dot{A}}$
So, $y_g>y_b$