3B Scientific SEK Optics - Manual (Page 75)

Exercise
Examine the operating principle of an astronomical telescope!
What do we need?
1 Base plate
1 Focusing lens “+50”
1 Focusing lens “+100”
1 Mask
additionally required:
1 Sheet of transparent paper
1 Scissors
1 Ruler
Conducting the experiment
1. Attach the mask to the base plate!
2. Insert focusing lens “+100” left into the base plate as marked on the mask!
3. Cut a square of 100 x 100 cm from a sheet of transparent paper and use it as a screen!
4. Hold the paper vertically behind the lens!
5. Direct the base plate with the lens onto a distant light object (window, tree etc.), so that its light
falls through the “+100” lens onto the screen!
6. Move the screen until the image of the object is focussed!
7. Place the “+50” lens onto the base plate and use it as a magnifying glass! Remove the screen and
look at the distant light object!
8. Describe your observations! Name features of the image! Draw the beam of light through the tele-
scope!
9. Compare the Dutch and the astronomical telescopes with regard to design and features of the im-
age!
10. Name fields of application for telescopes!
ELWE Physical experiments for education in natural science and engineering
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1 SEG - OP 6.5 Astronomical Telescope