Question

A convex lens of focal length 15 cm is used to form an image of the size of the object. Where from the lens should the object be placed?

Answer 1

Answer:

Object should be placed at 30 cm form the lens at curvature

Explanation:

Because the size of image is equal to the size of object...... As we know for f = r/2 and the f is 15 cm using this formula r=u=30 cm.... Here u is distance of object from lens