Electromagnets produce a magnetic field from an electrical current. Electromagnets can be found in the motors of everyday devices including cars, washing machines, refrigerators, and computers. The number of wire coils, type of nail, and voltage of the battery are a few factors that affect the strength of the magnetic field.
A group of students plans several investigations to test the factors affecting an electromagnetic field. First, they vary the number of times an insulated wire is wrapped around a steel nail. The ends of the wire are attached to each end of a 1.5 V battery to complete a simple circuit, as shown in the image.
The students record the maximum number of paper clips the magnet will lift for each trial.
Number of Coils Number of Paper Clips
10 3
20 7
30 9
40 12
Next, the students add a second battery and repeat the investigation.
They record the maximum number of paper clips the magnet will lift for each trial.
Number of Coils Number of Paper Clips
10 5
20 8
30 11
40 16
Then, they wrap insulated wire 25 times around different types of nails. The ends of the wire are attached to a single battery. The students record the properties of each type of nail and the maximum number of paper clips the magnet will lift for each trial.
Metal
Electrical Conductivity
Magnetic
(Yes/No)
Number of Paper Clips
Aluminum High conductivity No 0
Iron Medium conductivity Yes 15
Steel Low conductivity Yes 10
Multiple Choice Question
Which best describes the role of the nail in the electromagnetic field?
A.
The metallic properties act as a magnet
B.
The magnetic properties act as a magnet
C.
To conduct thermal energy through the magnetic field
D.
To conduct electrical current through the magnetic field
1 answer
The correct answer is:
B. The magnetic properties act as a magnet
In the context of the experiments, the nail's magnetic properties enhance the strength of the electromagnetic field produced by the current flowing through the wire coils. While the nail may also conduct electricity (as it's a metal), its primary role in this setup is to become magnetized by the magnetic field generated by the current.
