A straight, rigid conductor of length carries a steady current and is placed in a…
PHYSICS · Multi-part · AP · Physics 2: Algebra-based · Magnetism and Electromagnetism · Magnetism and Electromagnetism
Problem
A straight, rigid conductor of length L carries a steady current I and is placed in a region of uniform magnetic field of magnitude B. The angle between the direction of the current and the magnetic field is gradually varied from 0∘ to 90∘. Answer the following questions in detail.
(i) List the physical factors that decide the magnitude of the magnetic force experienced by the conductor and state how each factor affects the force.
(ii) Using suitable vector reasoning, explain how the direction of the magnetic force changes when the direction of current is reversed while the magnetic field is kept unchanged.
(iii) Show qualitatively that the magnitude of the magnetic force varies sinusoidally with the angle between the current direction and the magnetic field. Sketch the expected variation of force with angle from 0∘ to 180∘ and explain the symmetry of the graph.