Question

A convex lens forms a real and inverted image of a neddle at a distance of 50cm from it. where is the neddle placed in front of the convex lens if the image is equal to the size of the object? Also, find the power of the lens

Answer 1

according to question the size of image and object is equal so this can only happen when an object is placed at center of curvature.
so
object distance =u=-50
image distance =v=50

hope it will help you

Answer 2

here your answer
hope it is helpful for you