1. Look at the data table and graph for the 25-coil electromagnet. With the 1.5 V battery, the
electromagnet picked up an average of 6 paper clips, and with the 6.0 V battery, it picked up
an average of 23 paper clips.

a. About how many times stronger than the 1.5 V battery is the 6.0 V battery?
b. What is the approximate ratio of the number of paper clips picked up using the 6.0 V
battery to the number picked up using the 1.5 V battery?
c. Is this a direct relationship or an indirect relationship?

2. Look at the data table and graph for the 50-coil electromagnet. With the 1.5 V battery, the
electromagnet picked up an average of 13 paper clips, while the 25-coil electromagnet picked
up an average of 6 paper clips.

a. What is the ratio of the number of turns of the 50-turn electromagnet to the number of
turns of the 25-coil electromagnet?
b. What is the approximate ratio of the number of paper clips picked up by the 50-coil
electromagnet?

3. What does doubling the number of coils do to the strength of the electromagnet?
4. What does doubling the voltage do to the strength of the electromagnet?
5. Using the graph, predict how many paper clips a 7.5 V battery would pick up for both the 25-
coil electromagnet and the 50-coil electromagnet.

6. Calculate the slope of the 25-coil line and the 50-coil line to determine the average number of
paper clips that a 1 V battery would pick up.