# Lab report on electromagnets

Topics: Mathematics, Magnetic field, Average Pages: 7 (746 words) Published: March 20, 2014
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Science Lab on Electromagnets
By Caitlin Hendriks

Factors that Affect the Strength of an Electromagnet

Purpose:To test how two different factors, the number of loops and the current intensity, affect the strength of the magnetic field of an electromagnet.

Materials:Power pack, 4 connecting wires, switch, ammeter, paperclips, iron nail, copper wire.

PART A: TESTING THE NUMBER OF LOOPS

Procedure:
1. Create an electromagnet made of an iron nail with 5 loops of copper wire around it. 2. Draw a circuit diagram including the components in the materials list above, except the paperclips. 3.Build the circuit you drew in step 2, making sure all the switches are off. Show your teacher. 4. Turn the power pack on and adjust it to 7V.

5. Close the switch and count the number of paperclips the electromagnet can pick up at one time. 6. Turn the switch off and record the result.
7. Demagnetize the nail by tapping it on the table a few times. 8. Time permitting, repeat steps 5-7 for a total of 5 trials. 9. Repeat steps 1-8 (except step 2) with 10, 15, 20, and 25 loops. 10. Save the iron nail with 25 loops for Part B of the lab

Variables:
Independent: Number of loops within a circuit
Dependent: The number of paperclips per trial

Table 1: Measuring the Number of paperclips attracted to the electromagnet.

Number of Paperclips
Loops
Trial 1
Trial 2
Trial 3
Trial 4
Trial 5
5
1
0
2
1
2
10
3
2
4
3
5
15
4
7
5
5
8
20
6
2
4
5
5
25
6
7
8
6
6

Table 2: Averaging the numbers of paperclips per set of loops Loops
Average # of Paperclips
5
1.2
10
3.4
15
5.8
20
4.4
25
6.6

Sample Calculation:
1. Average (trial1 +trial 2+ trial 3+ trial 4+ trial 5 = answer / # of trials = average) 1+0+2+1+2 = 6/5 = 1.2

Observations:
1. Create a raw data table with the results collected.
2. Create a processed data table if more than one trial has been performed. Include formulas and sample calculations below the data table. 3. Make a graph to show the relationship between the independent and dependent variables.

Figure 1: Average number of paperclips per set of loops

Follow-Up Questions:

1.How do you think the results would have been affected if the iron nail used had zero loops of copper wire wrapped around it? Justify. It wouldn’t have worked since It wouldn’t have created a magnet because you wouldn’t have a core wrapped with wire and it won’t be magnetized. 2.How do you think the results would have been affected if the nail had been made of aluminum? Justify. Aluminum is not a ferromagnetic metal therefor it wouldn’t have worked. 3. Using the graph, estimate the number of paperclips that the electromagnet would have picked up if it had 30 loops of copper wire wrapped around it. Show your work (extrapolation = using the best fit line to estimate your answer) on the graph. Every set of loops it increases by 2.5 paperclips, therefor if you have 30 loops it would be 8 paperclips.

Conclusion:
If we increase the number of loops around an electromagnet we’re able to increase its strength. (it will also pick up more paperclips) PART B: TESTING VARIATIONS OF CURRENT INTENSITY

Procedure:
1. Use the electromagnet with 25 loops from the last step of Part A. 2. Use the same circuit that you build in Part A.
4. Close the switch and take the ammeter reading.
5. Count the number of paperclips the electromagnet can pick up at one time. 6. Open the switch and record your results.
7. Demagnetize the electromagnet.
8. Repeat steps 4-7 for a total of 5 trials.
9. Repeat steps 3-8 by increasing the potential difference by 1V each time.
Table 3: Measuring the amount of paperclips when the voltage of the power pack is raised by 1 every trial.

Number of Paperclips
Voltage (V)
Current Intensity (A)...