6A20.41 Projected Filament with Mirror
Concave mirror reflections, ray optics
A concave mirror reflects a real, inverted image of a light bulb filament onto the wall. Covering parts of the filament or mirror with an index card illustrates the nature of image formation under a ray optics model. Covering part of the mirror dims the image while covering part of the filament obscures the corresponding part of the reflected image.
-  U-shaped filament light bulb
-  Concave mirror
-  Index card
-  Lab stand
-  90-degree clamp
-  3-finger clamp
- Mount the light bulb to the lab stand using both a 3-finger clamp and a 90-degree clamp.
- Turn on the light bulb.
- Hold up a concave mirror facing the bulb and show that at a distance larger than the mirror's focal length, an inverted image of the filament appears on the wall.
- Ask the class what will happen if an index card covers part of the filament, and then do that experiment.
- Ask the class what will happen if an index card covers part of the mirror, and then do that experiment.
- PIRA 6A20.45
- Don't attempt this at home!
If you have any questions about the demos or notes you would like to add to this page, contact Ricky Chu at ricky_chu AT sfu DOT ca.