Electromagnet Lab Report

Words: 1276
Pages: 6

Testing the Strength of the Electromagnet by Changing the Number of Coils


The aim of this experiment is to investigate how the strength of an electromagnet is affected by the number of coil turns around the iron c-core.


As the number of wire coils increases, the strength of the magnetic field (the electromagnet’s strength) will also increase. This means that the number of paper clips that attach to the electromagnet will increase.

Explanation of Hypothesis/background:

When a DC (Direct Current) electric current flows through a wire, a magnetic field is created. Wrapping the wire in a coil concentrates and increases the magnetic field, because the additive effect of each turn of the wire. (When a coil of wire is used to create a magnetic field, it is
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Turn on the power source and leave it working for 30 seconds.
10. Count the number of paper clips attached to the electromagnet and record it (you have to count the paper clips with the power source switched on, otherwise they will fall off)
11. Turn the power source off, tap the iron c-core, in order to re-scramble the domains and rearrange the paper clips.
12. Repeat steps 3-11 three times for each coil turn.

Range of values and repetitions of the independent variable:

This experiment will be repeated three times for five different numbers of coils (independent variable). These are 20, 25, 30, 35 and 40 turns.
These values are enough since they provided a large range and would be sufficient to test the hypothesis.


A graph will be drawn with the number of coil turns on the x-axis and the number of paper clips attached to the electromagnet, on the y-axis. The graph will be entitled: The Number of Paper Clips Attached to the Electromagnet, against the Number of Coil Turns. (The graph should start from the origin because at 0 coil turns, there will be no magnetic field and hence no nails attached to the electromagnet. If it is not then there is a systemic error.)