A student observes the pattern formed by iron filings around a straight current-carrying conductor. The arrangement of filings demonstrates a property of magnetic fields. Which feature is illustrated by their pattern?
Circular symmetry of lines around the conductor
When current flows through a straight conductor that passes through a sheet of cardboard sprinkled with iron filings, the filings arrange themselves in concentric circles centred on the conductor once the cardboard is tapped gently.
This shows that the magnetic field lines of a straight current-carrying conductor are concentric circles around it, lying in planes perpendicular to the conductor, and their direction is given by the right-hand thumb rule. So the pattern illustrates the circular symmetry of the lines around the conductor.
The filings do not point straight out from the wire or line up along it, because the magnetic field of the current wraps around the conductor. They do not form random clusters at the ends either; collecting at the ends (poles) is the behaviour seen near a bar magnet, not around a straight wire.
Hence, Circular symmetry of lines around the conductor.
Similar Questions
What does the presence of parallel straight magnetic field lines inside a solenoid indicate?
Two parallel, straight wires carry equal currents in opposite directions. If the magnetic fields produced by the two wires are equal in magnitude and opposite in direction at a point, what is the resultant magnetic field at that point?
What happens to the magnetic field at the center of a circular coil when the number of turns is increased to n, assuming the current remains the same?
A student modifies the experiment by replacing the copper wire with a plastic thread between points X and Y, keeping all other conditions unchanged. What will be the expected observation regarding the compass needle and why?
When a compass is placed near the loop of a current-carrying circular coil, what does the compass needle’s alignment reveal about the field lines produced by the coil?
Important Questions from Magnetism
- The magnetic field around a straight current-carrying conductor:
Magnetic field is a quantity that has___________________ .
- The right-hand thumb rule is used to find which of the following?
- How are the magnetic field lines arranged inside a current-carrying solenoid?
- What does it mean when magnetic field lines are drawn closer together in a diagram?
