Question

in science class, students built the device pictured below using cardboard, wires, pipes, compasses, and a battery. when there is no electricity running through the wire, all the compass needles point toward earths magnetic north pole. when electric current is flowing through the wire, the compass needles change direction and point around the wire in a circle. as part of their investigation, the students moved each compass farther from the wire and wrote down their observations. what were the students most likely testing in this part of the investigation? a. the strength of the magnetic field b. the size of the compasses c. the direction that the current is flowing d. the force of gravity between the compasses and the wire

Explanation:

The students changed the distance of compasses from the wire. The magnetic - field strength around a current - carrying wire varies with distance. By moving compasses farther from the wire, they likely aimed to test how the magnetic - field strength changes with distance. The size of compasses, current direction, and gravity force between compasses and wire are not related to this distance - changing action.

Answer:

A. the strength of the magnetic field