A straight current-carrying conductor is placed in a uniform magnetic field and the…
PHYSICS · Multi-part · A Level · Physics · Fields and their consequences · Fields and their consequences
Problem
A straight current-carrying conductor is placed in a uniform magnetic field and the angle θ between the conductor and the magnetic field is slowly varied from 0∘ to 180∘.
(a) Part 1: (a) Describe qualitatively how the magnitude of the magnetic force on the conductor depends on θ, and sketch a labelled graph of force versus θ for the full range 0∘≤θ≤180∘.
(b) Part 2: (b) From your graph, identify the values of θ at which the force is zero and at which it attains its maximum value. Explain the physical reasons for these special angles.
(c) Part 3: (c) Using appropriate trigonometric reasoning, compare the magnitude of the force at θ=45∘ with that at θ=90∘, expressing your answer as a simple fraction of the maximum force.