Electricity: Battery & Bulb assignment
1) Get two small flashlight bulbs that work with D batteries. Also get at least one D
battery. Some teachers may have small bulbs for electric circuits in their science
classrooms. These would be great. Others may need to unscrew the light bulb
from a flashlight. Cheep flashlights can be purchased for a dollar or less, and their
light bulbs can be removed without too much trouble.
2) Have someone take a digital picture of you with one battery & one piece of wire
and the bulb lit. Use absolutely nothing other than the battery, wire, and bulb (no
bulb holders, no tape, and no more than one piece of wire). Again, using only
your hands, try getting the bulb to light with the same material and using
something else in addition. You will note immediately that this additional item
must be an electrical conductor. [I have had fifth graders come up to me showing
the bulb lit holding the pieces up to the braces on their teeth!]
3) Now use any wires or bulb holders or tape that you find useful. Using only one
battery take pictures of two different circuits, each with two bulbs lit. One circuit
should show both bulbs lit reasonably bright and the other circuit should show a
different circuit with bulbs much more dimly lit. The brightness should be due to
the way the circuit is designed, not due to a “bad connection” or low battery.
Depending on your particular bulb the “bright” configuration may not be all that
bright, and the “dim” configuration will be even dimmer. If you know the terms
“series” and “parallel”, you are trying to make one circuit of each type. If you do
not know these terms, try to get two bulbs lit entirely on your own, without help
from any person or written source, and then see if you can arrange the bulbs a
different way to get them a different brightness. If you have spent more than 30
minutes, then try getting some help. Your picture should be labeled as being the
“bright” or “dim” configuration.
4) Post to Blackboard your pictures and a written discussion of your experience
making the bulbs light. In your description, describe, draw, or photograph a
configuration of a battery, bulb, and wire that does NOT light the bulb and
attempt an explanation why. Also, attempt to explain why the bulbs are lit
brighter or dimmer in the two circuits. Based on the two circuits (brighter/
dimmer), explain how you think your house is wired and why.
5) Read the postings of your classmates.