Question

1) An object of height 3cm is placed 14 cm away from a convex lens of focal length 21cm. Find the position, type and the size of the image formed.
Or
2) A pot of depth 10 cm is filled with the liquid, due to this its base appears to be raised by 2 cm up from its original position, find the refractive index of the liquid. ​

Answer 1

Answer:

1 one answered

Explanation:

Given: h1=3cm;u=−14cm;f=−21cm

By lens formula, v1−u1=f1

v1−−141=−211

v=−8.4cm

Now, Magnification formula for lens, 

m=hh′=uv

h2=148.4×3

⇒h2=1.8cm

If the object is moved further away from the lens, the image will continue to move towards the lens and the size of the image will decrease with an increase in the distance.