The lines of force of a uniform magnetic field :

A uniform magnetic field is characterized by a constant magnitude and direction at all points in space. To represent such a field visually, the magnetic field lines must be parallel straight lines with equal spacing [c4]. This indicates that the field strength is the same everywhere, as the degree of closeness of field lines represents the relative strength of the field [c1][c3]. For instance, inside a current-carrying solenoid, the field lines are parallel straight lines, signifying a uniform magnetic field [c4]. Conversely, convergent or divergent lines would indicate a non-uniform field where the strength changes with position [c1]. Furthermore, magnetic field lines can never intersect because if they did, the magnetic field would have two different directions at the point of intersection, which is physically impossible [c1][t1][t4]. Therefore, for a field to be uniform, the lines must be parallel to each other.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 12: Magnetic Effects of Electric Current > Activity 12.3 > p. 197
2. [2] Science , class X (NCERT 2025 ed.) > Chapter 12: Magnetic Effects of Electric Current > What you have learnt > p. 206
3. [3] Science , class X (NCERT 2025 ed.) > Chapter 12: Magnetic Effects of Electric Current > 12.2.4 Magnetic Field due to a Current in a Solenoid > p. 201