A convex lens forms a real and inverted image of aneedle at a distance of 50cm from it. Where is the needle 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.

A convex lens forms a real and inverted image of aneedle at a distance

1.	A convex lens forms a real and inverted image of aneedle at a distance of 50cm from it. Where is the needle 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» Solution :Since the image is real and same SIZE. The position of image should be at 2F It is given that the image of the NEEDLE is formed at a distance of 50 cm from the convex lens. Hence, the needle is PLACED in front of the lens at a distance of 50 cm. Object distance, U = - 50 cm Image distance, V = 50 cm