Question

You have a lens whose focal length is –6.25 cm. You place an object on the axis of the lens at a distance of 10.7 cm from it. How far is the object\'s image from the lens (as a positive quantity)?

Answer 1

3.95 cm

Step-by-step explanation:

focal length of the lens, f = - 6.25 cm

distance of object from the lens, u = - 10.7 cm

Let the distance of image from the lens is v.

Use lens equation

`(1)/(f)=(1)/(v)-(1)/(u)`

`(1)/(-6.25)=(1)/(v)+(1)/(10.7)`

`(1)/(-6.25)-(1)/(10.7)=(1)/(v)`

`(1)/(v)=(-10.7-6.25)/(66.875)`

v = - 3.95 cm

Thus, the distance of image from the lens is 3.95 cm as the same side of object.