A convex lens is put 10cm from a light source and it makes sharp images on a screen, kept 10 cm from the lens. Now a glass block (refractive index 1.5) of 1.5 cm thickness is placed in contact with the light source. To get the sharp image again, the screen is shifted by a distance d. Then d is:
11 cm away from the lens
0
0.55 cm towards the lens
0.55 cm away from the lens
Refraction through parallel slab -
- wherein
shifting of object from slab
thickness of slab
Refractive Index of slab.
F = = 5 cm
Due to glass plate shift
s = t
= 1.5
= 0.5
New u =9.5 cm
Using lens formula
=
v = 10.55 cm
Shift is 0.55 cm away from the lens.
11 cm away from the lens
Option 2)0
Option 3)0.55 cm towards the lens
Option 4)0.55 cm away from the lens
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