Question

Renu works in a restaurant. She wants to arrange some plates on a shelf which is 12 cm in height. The height of a pile of 10 plates is 5 cm. Help her find out the maximum number of plates that she will be able to put on the shelf. (Hint: Find the thickness of 1 plate)

Answer 1

Answer:

NSWER

We know that,

v1+u1=f1

u = -15 cm

Focal length = -10 cm

∴v1=−101−(−15)1

⇒v1=−101+151=30−3+2=−301

⇒v=−30cm

Magnification (m)=uv=Object heightImage height

m=−uv=+−1530=−2

Also, Image height=−2×6=−12 cm

Therefore, a real, inverted and enlarged image of the object is formed beyond the centre of curvature