In Young's double slit experiment, two slits are illuminated with a light of wavelength $\lambda$. The line joining $A_1P$ is perpendicular to $A_1A_2$ as shown in figure. If the first minimum is detected at P, the value of slits separation 'a' will be
(D = distance between source and screen)

In Young's double slit experiment, the fringe width is 0.4 mm. What is the distance between $4^{\text{th}}$ dark band and $6^{\text{th}}$ bright band on the same side of the interference pattern?

The ratio of intensities at two points on the screen in Young's double slit experiment when waves from the two slits have a path difference of zero and $\lambda/4$ is ($\lambda$ is the wavelength of light used) ($\cos 0^\circ = 1$, $\cos\pi/2 = 0$)

In Young's double slit experiment, the distance between the slits is 3 mm and the slits are 2m away from the screen. Two interference patterns can be obtained on the screen due to light of wavelength 480 nm and 600 nm respectively. The separation on the screen between the $5^{\text{th}}$ order bright fringes on two interference patterns is