Table of Contents
Table of Contents
- Magnetic Field: In a Circular Loop
- Magnetic Field: In a Coil
- Magnetisation of an Iron Nail
- Summary
- What’s Next?
In the last segment, we learnt about the magnetic field pattern and magnetic field direction in a current-carrying wire. In this segment, we are going to learn about the magnetic field in a loop and also about the magnetisation of an iron nail due to electric current.
Magnetic Field: In a Circular Loop
A current-carrying loop also generates a magnetic field around it. The direction of the magnetic field in a loop can be determined by the Right-hand rule.
Right-hand rule
For any portion of the loop if place our thumb in the direction of the current then the fingers are curled in the direction of the magnetic field. Here also magnetic field exist in the form of concentric circles and the strength of the field decreases as we move away from the loop.
Magnetic Field Pattern: in a Loop
Inside the current-carrying loop magnetic field lines of all the portions of the loop interact with each other. As a result, there is a strong magnetic field inside the loop, especially at the centre. Thus, compared to a straight wire, a looped wire will generate a ‘stronger magnetic field’ assuming that the same current is flowing through both.
Magnetic Field: In a Coil
When a wire is looped multiple times it forms a coil. Again a current-carrying coil generates a magnetic field. A coil consists of multiple loops and each loop generates its own magnetic field. The resultant magnetic field thus generated is much stronger than the one generated by a single loop.
The magnetic field pattern of a coil is the same as that of a bar magnet.
Magnetic Field Pattern: in a Coil
Magnetisation of Iron Nail
An iron nail is a ferromagnetic material. So, when it is placed inside a current-carrying coil made of copper wire, it gets magnetised under the influence of the coil’s magnetic field. In fact, the magnetic field inside the coil gets stronger.
