Question

A needle lying on horizontal surface is viewed
vertically from a distance of 100 cm. A glass slab
of 12 cm thickness is placed on the needle. Find the
distance of the vertical image of the needle from the
eye, taking aūg = 1.5.
Ans. 96 cm.​

Answer 1

Answer:

∆t=(1-1/u1)h

where h is 12cm

and uair is 1.5

so,

∆t = (1-1/1.5)12

= 4 cm

therefore, needle will be at (100 - 4) = 96cm