A diverging lens always makes a reduced image. Could you use such a lens to start a fire by focusing sunlight? Explain.

1. A homeowner wishes to mount a floodlight on a wall of a swimming pool underwater so as to provide the maximum illumination of the surface of the pool for use at night. At what angle with respect to the wall would the light be pointed? The answer is 46 degrees. 2. In a slide projector, a slide is positioned 0.102 meters from a converging lens that has a focal length of 0.1 meters. At what distance from the lens must the screen be placed so that the image of the slide will be in focus? The answer is 5.1m 3. Compute the magnification for the slide projector in Q2. The answer is -50X

Spherical aberration is due to light rays O a. passing through the outer portions of a lens not focusing at the same point as rays that pass through the center O b. of different wavelength not focusing at the same point O C. passing through the lens in the vertical direction not focusing at the same point as rays passing through the lens in the horizontal direction O d. passing through the outer portions of a lens being absorbed more than rays that pass through the center

A converging lens of focal length 4 m produces a magnified image 2.4 times the size of the object. What is the object distance if the image is a) real? m b) virtual? m

can you use the formulas from the picture? thank you

*4. An object 3 mm high is placed 50 cm to the left of a converging lens of focal length 40 cm. A second converging lens with a focal length 10 cm is placed 220 cm to the right of the first lens. Where is the final image? Is it real or virtual? What will be the image size? Is it erect or inverted? 3 mm 1... -50 cm- f₁ = 40 cm 220 cm- f = 10 cm

If the screen is at the right position and the object is in a right position, the lens will focus the image of the object onto the screen.  If the screen is anywhere else, the object will look blurry or won't be seen.  The optical table has a meter-tape attached to the side, to give the position of the items. If the object is in a wrong position, the lens will defocus the light -- spread it out.  That means that the screen can't be placed anywhere to display a focused image.   If xL = 32.7 cm and the focal length is f = 20.8 cm, give a position (xO) that results in the light from the object spreading out.  (There are infinitely many such positions.)

2. Show that the minimum distance between a real object and its real image given by a convergent lens of focal length f is 4f. Get q as a function of p from 1/p + 1/q = 1/f. Take the derivative of s = p +q to find the value of p for which s is minimum.

Is it possible to obtain a non-inverted image with a converging spherical lens? Explain.

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