Understanding Forces on a Wire in a Magnetic Field for Beginners

AI Thread Summary
To calculate the forces on a wire in a magnetic field, use the formula F = BILsin(θ), where B is the magnetic field strength, I is the current, and L is the length of the wire. The angles 90°, 55°, 35°, and 0° refer to the orientation of the wire relative to the magnetic field, with 90° being perpendicular and 0° being parallel. The force will be maximum at 90° and zero at 0°, and the graph of force against sin(θ) will be sinusoidal, reflecting the relationship between force and the sine of the angle. Understanding these angles and their relationship to the magnetic field is crucial for completing the calculations and graphing tasks.
lightuplightup
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I don't understand this question at all- could someone please help- at least giving me a starting point- thanks

A wire, of length 70cm is placed into a magnetic field of strength 0.001T. If the wire carries a current of 5 amps
1/ Calculate the magnitude of the forces on the wire if it is successively oriented at 900, 550, 350 and parallel to the magnetic field
2/ Draw a graph showing the variation of the force as the angle changes
3/ What will be the shape of the graph if the force is plotted against sin0
4/ Draw a graph of force against sin0

I know for the first one you have to use F=BILsin0 but i don't understand the co-ordinates- what angle am i supposed to use- What does 900, 550 and 350 mean? I think if i get this first bit understood then i will be able to complete the other parts.

Thanks
 
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lightuplightup said:
I don't understand this question at all- could someone please help- at least giving me a starting point- thanks

A wire, of length 70cm is placed into a magnetic field of strength 0.001T. If the wire carries a current of 5 amps
1/ Calculate the magnitude of the forces on the wire if it is successively oriented at 900, 550, 350 and parallel to the magnetic field
2/ Draw a graph showing the variation of the force as the angle changes
3/ What will be the shape of the graph if the force is plotted against sin0
4/ Draw a graph of force against sin0

I know for the first one you have to use F=BILsin0 but i don't understand the co-ordinates- what angle am i supposed to use- What does 900, 550 and 350 mean? I think if i get this first bit understood then i will be able to complete the other parts.

Thanks

Look, you know that the magnitude of force is maximum and minimum when the angle between the field and current carrying wire is perpendicular and parallel respectively.(when BIL is constant).
So simply put in the values you are given into your formula and there we are.
I'm sure they are meant to be in degrees, and the angle theta is between the magnetic field and wire.
 
In the formula:

F=BIL\sin \theta

the angle is the smallest angle between the magnetic field vectors (or field lines) and the wire carrying the current.
 

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