Im making a graph of magnetic force vs current, after investigating the magnetic force exerted on a current-carrying wire, and how it varies with
current, length, magnetic field and angle.
How do I know when to use the point (0,0) on the graph?
To determine whether to include the point (0,0) on your graph of magnetic force versus current, you need to consider the physical scenario you are investigating.
The point (0,0) represents zero current and zero magnetic force. It is the intersection of the x-axis (current) and y-axis (magnetic force). Including this point on your graph depends on the specific nature of your experiment and the theoretical expectations for the relationship between magnetic force and current.
Consider the following scenarios:
1. No current, no magnetic force: If your experiment involves a situation where a current-carrying wire is not present, or where there is no magnetic field applied, it is reasonable to include the point (0,0) on the graph. This indicates that in the absence of a current or magnetic field, there is no magnetic force exerted on the wire.
2. Non-zero current, no magnetic force: If your experiment involves a scenario where there is a non-zero current but no magnetic field applied, it is expected that there will be no magnetic force exerted on the wire. In this case, you would not include the point (0,0) on the graph since the absence of a magnetic field means there should still be no magnetic force.
3. Non-zero current, non-zero magnetic force: In many cases, the relationship between magnetic force and current is not expected to be linear, and the magnetic force may not be zero even when the current is zero. This could be due to factors such as the presence of a magnetic field from a permanent magnet or the geometry of the wire configuration. In such cases, it would not be appropriate to include the point (0,0) on the graph.
In summary, whether to include the point (0,0) on your graph depends on the specific circumstances of your experiment. Consider the theoretical expectations and the physical conditions involved to determine whether zero current corresponds to zero magnetic force, which would then warrant including the point (0,0) on the graph.