By what factor will the size of an object placed 10cm from a convex lens be increased if the image is seen on a screen placed 25cm from the lens?

Answer Details

This question is related to the magnification produced by a convex lens. Magnification is the ratio of the size of the image produced by a lens to the size of the object placed in front of the lens. In this question, we are given that the object is placed 10 cm from the lens and the image is formed at a distance of 25 cm from the lens.
To find the magnification produced by the lens, we can use the formula:
magnification = image size / object size = image distance / object distance
We are not given the size of the object, but we can still find the magnification by using the given distances.
image distance = 25 cm
object distance = 10 cm
So, the magnification produced by the lens is:
magnification = image distance / object distance = 25 cm / 10 cm = 2.5
This means that the image formed by the lens is 2.5 times larger than the object placed in front of it. Therefore, the answer is option B: 2.5.