Optics - lenses, telescopes, microscopes, and optical fibers

 

1 Rays

1 What is the difference between a real and a virtual image?

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2 What two rays are the simplest to choose when drawing a ray diagram?

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3 What effect does increasing the height of the object in a ray diagram have on the predicted image position?

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4 Why is the formula method for predicting the position of an image equivalent to drawing an accurate ray diagram?

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5 How many images of a distant light are seen by reflection in a simple two surface lens. What determines where the images are located?

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2 The thin lens formula

1 By what principle is the lens formula normally proved from ray diagrams?

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2 How exactly is the ray diagram drawn for a magnifying glass?

 

 

 

 

 

Draw one

3 How is the formula changed if an image becomes virtual?

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4 Is the formula more accurate than a ray diagram (in principle and in practice)?

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5 How is the simple convex-lens-real-image-formula modified to predict the image position in a convex mirror?

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3 Telescopes

1 Which telescope (of historical importance) had a concave eyepiece?

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2 How do you find the magnification of a refracting telescope?

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3 Who made the first reflecting telescope (and why)?

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4 Why are all large modern telescopes reflecting instruments?

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4 Microscopes

1 Which of the two lenses in a simple microscope has the shorter focal length?

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2 Where is the object placed to produce the first (real) magnified image?

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3 Where is the final image normally formed?

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4 How is the magnification of a microscope related to the power of the component lenses?

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5 Optical fibers

1 What part does total internal reflection play in the operation of a simple glass optical fiber?

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2 Why do glass optical fibers have a plastic covering? (Two reasons)

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3 What wavelength of light is used for the transmission of signals on optical cables (and why)?

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4* How is it possible simply to calculate the maximum angle of incidence for which a ray will be totally internally reflected in a simple optical fiber?

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6 Lens defects

1 What causes chromatic aberration and how is it countered?

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2 What effect on an image is caused by spherical aberration?

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3 How might a student reduce spherical aberration in a simple demonstration astronomical telescope?

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4 How is spherical aberration eliminated in a large astronomical reflecting telescope?

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5 What briefly are; barrel distortion, pincushion distortion and coma? When would you be most likely to notice these effects?

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7 Two lenses in contact and multiple lenses

1 What is the formula for finding the focal length of two lenses in contact?

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2 What is is the definition of the power of a lens?

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3 How could you find the focal length of a concave lens using a real image of the Sun?

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4 Why is it perfectly sensible (in his own mind) for Dr. Dolittle, in the children's story books, to wear four pairs of glasses at once?

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8 Rayleigh's criterion for resolution

1 What is the width of the central maximum of the diffraction pattern of a single slit (I want a formula for it)?

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2 How is this relationship modified for a small circular hole?

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3 What is Rayleigh's criterion for the resolution of two point sources ..... and why is it somewhat arbitrary?

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4 What examples could IB use to ask questions on this topic?

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