In Young's double-slit experiment, the separation between the two slits is d and the wavelength of the light is $\lambda$. The intensity of light falling on slit 1 is four times the intensity of light falling on the slit 2. Choose the correct choice(s)

For $d=\lambda$, there will be only one, central maxima.

For $\lambda <d<2\lambda$, there will be three maximas on the screen corresponding to path difference, $∆x=0$ and $∆x=\pm \lambda$

If intensities of light emerging from the two slits are equal to that of the light emerging from slit 1 ,then intensity of dark fringe decreases and intensity of bright fringe also increases.

If intensities of light emerging from the two slits are equal to that of the light emerging from slit 2, then intensity of dark fringe decreases and intensity of bright fringe also decreases.