Monochromatic light of wavelength 5000 Å is incident on two slits separated by a distance of $5 × 10^{–4} m$. Interference pattern is seen on the screen placed at a distance of 1 m from the slits. A thin glass plate of thickness $1.5 × 10^{–6} m$ and refractive index 1.5 is laced between one of the slits and the screen. If intensity in the absence of plate was Io then new intensity at the centre of the screen will be

$I_0$

$\frac{xd}{D}=(μ-1)t$

or $x=\frac{(μ-1)tDt}{d}=\frac{(1.5-1)×1.5×10^{-6}×1}{5×10^{-4}}$

$1.5×10^{-3}m$