light - tracing the image-exercises cont.

Solution to question 7.

Look at the animation above. A magnified, virtual and upright image is formed when the object is within one focal length to the lens.

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Click to see a 120 kb movie of an image formed with a convex lens.

The lens is curved in the horizontal and vertical planes.

The image therefore appears inverted and moves from right to left when the object is moving left to right.

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Tracing images(convex lens) exercises continued
1. How can you quickly find the focal length of a lens? Click for solution 2. An object placed 12.0 m from a lens forms an inverted image which is 20 cm from the lens. Describe the image formed if the object is 20 cm from the lens? Click for solution 3. You have a convex lens with focal length 50 cm. Describe the image formed if the object is a) 200cm from the lens b) 50cm from the lens c) 25cm from the lens Click for solution 3. What is the necessary condition for a convex lens to act as a magnifying glass? Click for solution 6. Select three of the four adjectives listed below to describe the image formed by a lens used as a magnifying glass. (erect, inverted, diminished, enlarged, real, virtual) Click for solution.
7) Look at the image produced by a magnifying glass. The magnifying glass has a focal length of 10cms. Describe the image and indicate approximately how far the object is from the lens. Click for solution. Try some exercises with Images created by glass cylinders. (Curvature in one plane.) 8) Many bushfires are started by discarded bottles. Explain why. 9) Irene uses a convex lens to project a clear image of a distant window onto a screen. Her son walks from left to right just outside the windo. Describe the image formed.Solution
Continue with exercises with combined lenses