Purpose : Construct a circuit from a circuit diagram and use a ammeter to correctly measure current

Materials : 1.5 V cell, 3 Various bulbs(1.5V/ 3.0V/ 6.0V), connecting wires, switch, ammeter

Procedure :

1. Construct the following circuit, using one of the light bulbs (leave the switch open)
2. Close the switch brielfy and measure the current
3. Repeat step 3 with the remaining light bulbs

Observations :

• Our group didn’t use the switch
• The bulb was turned on lightly

Result : 

Bulb type (V)              Measured Current (A)

Small                            0.4 A

Big                                 0.6 A

Oblong                          0.5 A

 

What did you find out?

1. Which circuit had the largest current?  The big bulb had the largest current

2. Which circuit had the smallest current? The small bulb had the smallest current

3. What is the purpose of the switch in this circuit? To allow and not allow currents to flow

4. When you measure an unknown current, you should start with the meter set to a large current scale and the decrease the scale. Explain the purpose of starting with a higher setting.      You can always make the scale smaller if it’s too large and it is easier to read on a larger scale than a smaller scale