A straight, lightweight metal rod of length 0.30 m is oriented vertically and is…
PHYSICS · Multi-part · A Level · Physics · Fields and their consequences · Fields and their consequences
Problem
A straight, lightweight metal rod of length 0.30 m is oriented vertically and is being transported due east at a constant speed of 5.0 m s⁻¹ through Earth’s local magnetic field, which in the region of motion is uniform and directed horizontally toward geographic north with magnitude 0.40 T.
Assume the rod is isolated except for the free charges it contains.
(1) Identify which end of the rod (top or bottom) becomes positively charged as it moves and state the reason for this charge separation.
(2) Describe the direction of the induced electric field that develops inside the rod as a consequence of the charge separation and explain how this field relates to the motion of the charges.
(3) If the rod were instead moved due west with the same speed and orientation, explain how (if at all) the polarity of the rod and the direction of the internal electric field would change.