Question

How can the distance between the first bright band and the central band be increased in a double-slit experiment?

Answer 1

Answer:

Decrease the slit separation, increase the distance of the screen from the slits, and increase the wavelength.

Explanation:

The distance $y$ from the central band to the first bright band is given by

$y = \dfrac{ \lambda D}{d}$

where $\lambda$ is the wavelength of light (or any particle), $D$ is the distance to the screen, and $d$ is the slit separation.

From this equation we see that, by increasing the wavelength $\lambda$ , increasing the distance from the screen $D$, and decreasing the slit separation $d$, we increase the distance between the first bright band and the central band.

Therefore, the 2nd choice "Decrease the slit separation, increase the distance of the screen from the slits, and increase the wavelength." is correct.