Two long, parallel, straight wires and are fixed in air at a distance of from each…
PHYSICS · Subjective · AP · Physics 2: Algebra-based · Magnetism and Electromagnetism · Magnetism and Electromagnetism
Problem
Two long, parallel, straight wires A and B are fixed in air at a distance of 8cm from each other. Wire A carries a current of 5A vertically upward while wire B carries an equal current vertically downward.
(i) At the point P which is exactly midway between the two wires, state the direction of the resultant magnetic field.
(ii) At the point Q which lies 4cm to the right of wire B (i.e., on the side away from wire A), state the direction of the resultant magnetic field.
(iii) If the direction of current in wire B is now reversed while that in wire A remains unchanged, describe how the directions obtained in parts (i) and (ii) will alter.
(iv) Rank qualitatively (largest to smallest) the magnitudes of the magnetic field at the points P and Q for both current configurations, giving justification without numerical calculation. Support your answers with clear, labelled sketches.