The corkscrew rule and the right hand
The first to formulate a rule of thumb, was the physicist Peter Gimlet. This rule is very useful if you want to define the magnetic field as the direction of tension.
A rule of thumb, you can use only in the case if the magnetic field is straight in relation to the conductor.
The corkscrew rule States that the orientation of the magnetic field coincides with the orientation of the handle of the gimlet, gimlet if the right thread is screwed in the direction of the current.
The application of this rule is possible in the solenoid. Then the rule of thumb is: a large protruding finger of the right hand indicate the direction of lines of magnetic induction, if you wrap it around the solenoid so that the fingers pointed to the direction of the current in the coils.
A solenoid is a coil of tightly wound coils. Prerequisite - coil length should be significantly larger than the diameter.
Right-hand rule, is opposite to the rule of the gimlet, but with a more user-friendly wording which is used more often.
The right-hand rule sounds like - grasp the investigated element of the right hand so that the fingers of the clenched fist pointing to the direction of the magnetic lines, in this case, when the forward movement in the direction of the magnetic lines of the large bent 90 degrees to the palm, the thumb will indicate the direction of current.
If in the problem described moving the vehicle, the right-hand rule, specify so: position the arm so that the field lines perpendicularly entered the palm, and the thumb extended perpendicular to it, must indicate the direction of motion of conductor, then the remaining four protruding fingers will be aimed in the same way as the induction current.
The left-hand rule
Place the left palm so that four fingers pointing to the direction of electric current in the conductor, while the lines of induction must be in the hand at an angle of 90 degrees, then bent the thumb will indicate the direction of the current on the conductor forces.
Most often this rule is used to determine the direction that will deviate Explorer. This refers to the situation where a conductor placed between two magnets and let it talk.
There is a second formulation of the rule of the left hand. Four fingers of the left hand should be positioned in the direction of motion of positively or negatively charged particles electric current, the lines of induction created by the magnetic field should perpendicularly enter the palm. In this case, the direction of the ampere force or the Lorentz force will point protruding thumb of the left hand.