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
The direction of the magnetic field at the centre of a current-carrying circular loop is determined by which of the following?
A single-turn coil of radius R produces a magnetic field B at its centre. If the same wire is wound into a coil of n turns (each of radius R/n) carrying the same current I, what will be the value of the new field at the centre?
An electron enters a uniform magnetic field at right angles to it. If the magnetic field is directed into the page and the electron enters toward the right, what is the direction of the force acting on the electron?
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Why does one end of a solenoid behave as a north pole and the other as a south pole?
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A rectangular coil is placed in a uniform magnetic field. If the direction of the current is reversed, what is the effect on the force acting on each segment of the coil?
A student uses Fleming's Left Hand Rule to determine the direction of force on a conductor. If the forefinger points north, and the middle finger points east, in which direction will the force act?
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Important Questions from Magnetism
What is the direction of magnetic field lines outside a magnet?
Which of the following statement is correct?
।. Magnetic field has both magnitude and direction.
II. The magnetic field inside a current-carrying straight long solenoid is the same at all points.
The magnetic effect of electric current was discovered by _____.
The important property of magnet which was exploited by navigators and travelers from the ancient times is:
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____.
