by Alan Zisman (c) 2003
Resistors soak up some electrical current, helping to keep it from getting too strong. We’re going to experiment with resistors in our circuit.
Resistors are labelled with coloured stripes, which tell how powerful they are-- resistance is measured in ohms.
Open the Virtual Electricity Lab. Create a circuit using:
-- two 12 volt batteries
-- the first light bulb
-- a switch
-- one of the
first three resistors in the set. When you select a resistor, you’ll see
its capacity listed on top.
1. Write down the capacity of the resistor you selected:
________ Ohms _______ Watts
Stripes: _________ ___________ _________ _________
Your circuit should look something like this:
2. Turn on the switch... What happened to the resistor? Why do you think this happened?
3. Did the light bulb light up? Why do you think that happened?
4. Flip the switch (to off). Remove the burnt-out resistor. Replace it with the sixth resistor (500 ohm, 5 watts... green, black, brown, and yellow stripes). Turn the switch on again.
a) What happened to the resistor?
b) Did the light bulb light up? Why do you think this happened?
5. Remove the resistor, and add two of the 5th resistor: 100 ohm/5 watts-- brown, black, brown, and yellow stripes... in a circuit like this:
Did the light bulb light up? Why do you think this happened?