Page 21 - 10-phy-12 Geometrical Optics

Post Lab. 1. Take three more readings in the above experiment and draw a graph
Activities between (pq) along y-axis and (p+q) along x-axis. Find the slope or
gradient of the graph. What does this slope represent?
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2. How can you make a set of rays coming from a single point to form a
parallel beam of light?
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3. By measuring approximate focal length of different convex lenses,
investigate, how the focal length of a lens is related to its thickness?
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4. Explain the difference between a real image and virtual image.
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BRAIN TEASER
1. If object needle is replaced by a lighted candle, what arrangement would be

needed to obtain its image?
2. Would you be able to obtain the image of the candle on a screen if it is

placed within the focal length of the lens? Explain with the help of a ray
diagram.
3. If half of a convex lens is covered by an opaque object, what shape of image
would be obtained on the screen?

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