A thin equiconvex lens of reflective index 3/2 is placed on a horizontal plane mirror as shown in figure. The space between the lens and mirror is filled with a liquid of refractive index 4/3 It is found that when a point object is placed 15 cm above the lens on its principal axis, the object coincides with its own image.
If another liquid is filled instead of water, the object and the image coincide at a distance 25 cm from the lens. Calculate the refractive index of the liquid.
(a) 1.6
(2) 2.6
(3) 2.8
(4) 3.2
