The concept of field lines is a visual representation of the direction and strength of an electric or magnetic field. These lines indicate the direction in which a positive charge would move if placed in the field. The closer the lines are together, the stronger the field is at that point.
Potential is the amount of energy per unit charge at a specific point in an electric field. The potential at a point is equal to the work done per unit charge to move a test charge from infinity to that point. The potential difference between two points in an electric field is equal to the change in potential energy per unit charge.
The strength of an electric or magnetic field is indicated by the density of field lines. The closer the lines are together, the stronger the field is at that point. This is because the field lines are used to represent the direction and magnitude of the force that a positive charge would experience at that point.
Coilinearity refers to the parallel alignment of field lines in a uniform electric or magnetic field. In such a field, all field lines are parallel and evenly spaced, indicating a constant field strength. This is often seen in the field produced by a long straight wire or a pair of parallel plates.
The shape of a coil affects its field lines by causing them to curve and loop around the coil. This is because the current flowing through the coil creates a magnetic field, and the shape of the coil determines the direction and strength of this field. A tightly wound coil will have more closely packed field lines, while a loosely wound coil will have more spread out field lines.