A metallic solid sphere is placed in a uniform electric field. The lines of force follow the paths (s) shown in figure as

When metallic solid sphere is placed in a uniform electric field, the electrons of the sphere will move against the direction of the electric field. Consequently, the left face of the sphere acquires negative charge while the right face attains positive charge. The field lines will terminate at the left face of sphere and restart from its right face. The electric field inside the sphere is zero. On the surface of the sphere, the field lines are normal at every point i.e., directed towards the centre. Therefore, the correct field line is represented by line 4.