Right-hand grip rule is used to determine the direction of a magnetic field from the current direction in a conducting wire. It says that if the right hand grips the wire so that the thumb points the same way as the current, the fingers curls the same way as the field lines.
The magnetic field direction of a solenoid or a coil can be determined by the right-hand grip rule for solenoid as follows:
16.2 Magnetic field of electric currents
Pronunciation in English (listen with default application).