An electric current generates a magnetic field. The right-hand grip rule is a helpful mnemonic to determine the direction of the magnetic field produced by the current. Point the thumb of your right hand in the direction of the electric current; your fingers will then curl in the direction of the circular magnetic field lines.
Here, the spacing of the field lines is improved to reflect that the field strength \( B = \mu_0 I / (2\pi r) \) is higher near the wire (so lines appear more densely packed). As \(I\) increases, more lines appear overall, and their spacing near the wire is tighter, indicating a stronger magnetic field.