If the current through the wire remains the same, what happens to the deflection of the compass needle when it is moved away from the copper wire?

When the current through the wire remains constant, the deflection of the compass needle decreases as it is moved away from the copper wire. This phenomenon can be attributed to the way magnetic fields behave around current-carrying conductors. The strength of the magnetic field is inversely proportional to the square of the distance from the wire, following the inverse square law. As the compass is moved farther from the wire, the magnetic field at its location weakens, leading to a reduced deflection of the compass needle. The magnetic influence on the needle diminishes with increasing distance, resulting in a proportional decrease in the observed deflection. This relationship underscores the importance of distance in determining the impact of a current’s magnetic field on nearby objects, as exemplified by the compass needle’s changing deflection.