The near vision of an average person is `25 cm`. To view an object with an angular magnification of `10`, what should be the power of the microscope ?

Explanation

The least distance of fistinct vision of an average person
(i.e.,D) is 25 cm, in order to view an object with magnification 10,
Here, v-D-25 cm and u=f
But the magnification m=v/u=D/f
`" " m=(D)/(f)`
`rArr" "f=(D)/(m)=(25)/(10)=2.5 =0.025m`
`" " p=(1)/(0.025)=40D`
This is the required power of lens