A single circular loop of wire of radius 5 cm lies flat on a horizontal table
PHYSICS · Multi-part · CBSE · Physics · Moving Charges and Magnetism · Moving Charges and Magnetism
Problem
A single circular loop of wire of radius 5 cm lies flat on a horizontal table. When viewed from above, the current in the loop flows clockwise. A grid of small compasses placed around the loop shows their needles tangential to circles centered on the loop and pointing clockwise when viewed from above.
(a) From the compass observations, identify which face of the loop behaves as a magnetic North pole and justify your answer.
(b) On a separate sheet, draw at least four representative magnetic field lines in the region above the table (outside the wire) produced by the loop. Indicate the direction of each line.
(c) A second, identical loop carrying the same current in the same direction is placed coaxially 10 cm directly above the first loop. Predict qualitatively how the resultant magnetic field magnitude along the common axis changes at the midpoint between the two loops compared with the field that existed there before the second loop was added. Justify your reasoning by considering superposition.
(d) Without performing a numerical calculation, discuss whether a point exists on the common axis between the two loops where the net magnetic field is zero. Explain the reasoning leading to your conclusion.