Rules of the left and right hand allow to define physical processes and to find the directions of magnetic lines, the directions of current and other physical quantities.
Rule of the gimlet and right hand
The physicist Pyotr Buravchik was the first who formulated the rule of the gimlet. This rule is very convenient if it is necessary to define such characteristic of magnetic field as orientation of tension.
The rule of the gimlet can be involved only if magnetic field is located rectilinearly in relation to the conductor with current.
The rule of the gimlet says that the orientation of magnetic field will coincide with orientation of the handle of the gimlet if the gimlet with the right cutting is twisted in the direction of current.
Application of this rule is possible also in the solenoid. Then the rule of the gimlet sounds so: the big bulged finger of the right hand will specify the direction of lines of magnetic induction if to clasp the solenoid so that fingers indicated the direction of current in rounds.
The solenoid - is the coil with densely reeled up rounds. An indispensable condition - length of the coil has to be much more, than diameter.
The rule of the right hand is the return to the rule to the gimlet, but with more convenient and clear formulation because of what is used much more often. The rule of the right hand sounds so - clasp the studied element with the right hand so that fingers of the clenched fist specified the direction of magnetic lines, in that case at progress in the direction of magnetic lines the big finger unbent by 90 degrees concerning a palm will specify the direction of current. If in a task the moving conductor is described, then the rule of the right hand will be formulated so: arrange a hand so that power lines of the field were included perpendicularly into a palm, and the thumb extended perpendicularly has to specify the direction of the movement of the conductor, then the bulged four remained fingers will be directed as well as induction current.
Rule of the left hand
Arrange the left palm so that four fingers specified the direction of electric current in the conductor, at the same time lines of induction have to enter a palm at an angle of 90 degrees, then the unbent thumb will specify the direction of force operating on the conductor.
Most often this rule is used for definition of the direction by which the conductor will deviate. The situation when the conductor have between two magnets means and start up on it current.
There is also the second wording of the rule of the left hand. Four fingers of the left hand have to be located in the direction of the movement positively or negatively charged particles of electric current, the line of induction of the created magnetic field have to enter a palm perpendicularly. In that case the direction of Ampere force or Lorentz force will specify the bulged thumb of the left hand.