Final answer:
Two convex lenses create images at different locations depending on their focal lengths and the object's position relative to them. One lens produces an image at infinity, highly magnified and inverted, while the other creates an inverted and diminished image between the focal point and twice the focal length.
Step-by-step explanation:
When two convex lenses with focal lengths of 20 cm and 10 cm are placed 30 cm apart, and an object of 2.0 cm height is placed midway (which is 15 cm from each lens), we will have to analyze the image formation by each lens separately. For the first lens (20 cm focal length), the object is placed at a distance equal to the focal length, meaning the image will be formed at infinity and it will be highly magnified and inverted. For the second lens (10 cm focal length), the object is beyond 2 focal lengths away, which will create an inverted and diminished image between the focal point and twice the focal length on the right side of the lens.
For the observation from the left through the lens with longer focal length, you will see no distinct image as the rays haven't converged to form one due to the object being exactly at the focal point. On the contrary, viewing from the right through the lens with the shorter focal length, an inverted, diminished image closer to the lens than the object can be seen. The magnification can be calculated using the thin lens equation, which gives the relationship between the object distance, image distance, and focal length of the lens.