Table of Contents
Table of Contents
- Magnetic Field due to a Current-Carrying Conductor
- Right-Hand Thumb Rule
- Summary
- What’s Next?
In the previous segment, we have learnt about the magnetic field and the magnetic field lines. In this segment, we will understand the magnetic field created due to a current-carrying conductor.
Magnetic field due to a current-carrying conductor
- A current-carrying wire produces a magnetic field. Thus, any current-carrying conductor should also create a pattern of magnetic field lines.
- Take a copper wire, pass it vertically through a cardboard and connect it to a circuit as shown.
Circuit to determine the magnetic field of a current-carrying conductor
- Sprinkle some iron filings on the cardboard and plug in the key. When the current starts to flow in the wire, the iron filings which were randomly arranged earlier align themselves in concentric circles around the wire. These concentric circles represent the magnetic field lines of a current-carrying wire.
Magnetic field of a current-carrying conductor
- If we want to find the direction of the magnetic field at a point, place a magnetic compass at that point and the direction of the north pole of the compass gives the direction of the field at that point.
- Also on reversing the direction of the current, the north pole of the compass needle points exactly opposite to its initial position at the same point.
- If we increase or decrease the current in the wire then the deflection of the compass needle also varies accordingly.
- Hence, we can say that the strength of the magnetic field also changes with the magnitude of current passing through the wire.
What is the Right-hand thumb rule?
- Imagine that you are holding your right hand around a current-carrying conductor and your thumb points in the direction of the current, then the direction in which the fingers curl gives the direction of the magnetic field lines. This is known as the right-hand thumb rule.
