(a) State the mathematical expression for the magnitude of the magnetic force experienced by a straight current-carrying conductor placed in a uniform magnetic field. Briefly explain the physical meaning of each symbol used.
(b) Keeping the current I, length L and magnetic field strength B fixed, describe qualitatively how the magnitude of the force changes as the angle θ between the conductor and the field is varied from 0∘ to 90∘. Use appropriate reasoning to support your answer.