A technician wants to decrease the magnetic effect around a current-carrying wire without changing the wire's material or environment. Which method should be used?
Reduce the amount of current flowing through the wire
The magnetic field around a straight current-carrying wire is given by B = µ0I ⁄ (2πr), so the strength of the field at a given distance depends directly on the current I flowing through the wire. To weaken the magnetic effect without changing the material or the surroundings, the current must be reduced.
Increasing the length of the wire or making it thinner does not change B at a fixed distance for a given current; a thinner wire only heats up more. Bending the wire into a straight line actually keeps the field pattern the same and, for a coil, would even strengthen the field along the axis. Only lowering the current reliably reduces the magnetic effect.
Hence, the answer is Reduce the amount of current flowing through the wire.
Similar Questions
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Important Questions from Magnetism
The magnet used to lift and transport heavy loads like big metals, steel girders and scrap iron objects for loading and unloading purposes is known as____.
A suspended bar magnet is rotated. It will come to rest in the north-south direction. This shows that the earth has its own_______.
When a bar magnet is cut into two equal parts, then:
Consider the following statements about a magnetic field.
(i) A magnetic field has both magnitude and direction.
(ii) The direction of magnetic field lines inside a bar magnet is from its south pole to its north pole.
(iii) Magnetic field lines are closed curves.
Select the correct option.
What will happen if a collection of positive and negative charges are passed at a high speed through a magnetic field which is perpendicular to the direction of motion of the charges? (Assume that both kind of charges are NOT going to recombine)
