Question

1. Describe with the use of illustrations the magnetic field associated with DC current flow in a linear conductor. Make sure you indicate the relationship between the direction of current flow and the direction of the resultant magnetic field.

2. Describe with the use of illustrations the magnetic field associated with DC current flow in a coiled conductor. Make sure you indicate the relationship between the direction of current flow and the direction of the resultant magnetic field.

Answer 1

This direction can be deduced by holding the current carrying conductor in your left hand with the thumb extended pointing in the direction of the electron flow from negative to positive.

The position of the fingers laid across and around the conductor will now be pointing in the direction of the generated magnetic lines of force as shown.

If the direction of the electron flowing through the conductor is reversed, the left hand will need to be placed onto the other side of the conductor with the thumb pointing in the new direction of the electron current flow. the direction of the magnetic field depends upon the direction of current flow.

The magnetic flux developed around the coil being proportional to the amount of current flowing in the coils windings as shown. If additional layers of wire are wound upon the same coil with the same current flowing through them, the static magnetic field strength would be increased.

If the wire is then wound into a coil, the magnetic field is greatly intensified producing a static magnetic field around itself forming the shape of a bar magnet giving a distinct North and South pole.