If the compass is moved farther from the conducting wire (e.g., at point Q) while maintaining a constant current, the deflection in the needle decreases. The magnetic field strength decreases with an increase in distance from the current-carrying conductor.
What happens to the deflection of the needle if the compass is moved away from the copper wire while keeping the current constant?
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If the compass is moved away from the copper wire while keeping the current constant, the deflection of the needle decreases. The deflection of the compass needle is directly related to the strength of the magnetic field produced by the current in the wire.
As the distance between the compass and the current-carrying copper wire increases, the magnetic field experienced by the compass becomes weaker. The relationship between the magnetic field strength (B), current (I), and the distance from the wire (r) follows an inverse square law, expressed as B ∝ 1/r². Therefore, as the distance increases, the magnetic field strength decreases, resulting in a reduced deflection of the compass needle.
In summary, maintaining a constant current but moving the compass away from the copper wire leads to a decrease in the deflection of the needle due to the diminishing strength of the magnetic field with increasing distance.