Table of Contents
Table of Contents
- Solenoid
- Magnetic Field in Solenoid
- Summary
- Did You Know?
- What’s Next?
In the previous segment, we have seen the magnetic field created due to a current through a circular loop. In this segment, we will study the magnetic field due to a current in a solenoid.
What is a Solenoid?
- A solenoid is a long cylindrical coil that has many circular turns of insulated copper wire, wrapped closely in the shape of a cylinder.
- On passing an electric current through the copper wire, each turn of the coil behaves like a magnet.
Solenoid
- If we pass the current through the coil in the clockwise direction and bring the south pole of a bar magnet close to the left side of the solenoid, then the bar magnet will be repelled by the solenoid.
- If we bring the north pole of the bar magnet close to the left side, it will be attracted. Thus, the left-hand side of the solenoid is acting like the south pole.
- Also, if we perform the same activity on the right-hand side of the solenoid, we will notice that the right-hand side acts as the north pole.
Clockwise flow of current in a solenoid
- If we reverse the flow of current, the left-hand side of the solenoid will act as the north pole and the right-hand side will act like the south pole.
Anticlockwise flow of current in a solenoid
Magnetic field in Solenoid
- The magnetic field pattern of a solenoid is similar to that of a bar magnet. Within the loop, the field lines go from the south pole to the north pole and outside the loop, they go from the north pole to the south pole.
