The force on a straight conductor of length L carrying current I in a magnetic field B is given by
Correct answer: A. F equals BIL sin theta
- A. F equals BIL sin theta
- B. F equals BIL cos theta
- C. F equals BI over L
- D. F equals B over IL
Explanation
The sine factor means the force is maximum when the conductor is perpendicular to the field and zero when it lies along the field, since a current parallel to B feels no force at all. The direction is given by Fleming's left hand rule, at right angles to both the current and the field. This force is what turns an electric motor.
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About Magnetic Flux Density
Magnetic flux density measures the magnetic force acting on a current carrying conductor or moving charge in a magnetic field. Work includes the relations B equals F divided by IL and F equals qvB, the tesla as its SI unit, field direction and the distinction between flux density and magnetic flux.
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