you need
  • - magnet;
  • - magnetic needle;
  • - gimlet.
Determine direction vector induction in the permanent magnet.First, find north and south poles in a magnet - the north is usually painted in blue and marked with the Latin letter N, and the southern painted in red and put the letter S. If the paint marks on the magnet is not, define the pole with a magnetic needle with known poles.
Select the arrow next to the magnet to one end of the arrow was attracted to him.If the magnet was attracted to the south pole of the arrow, then a magnet is the north pole.If, on the contrary, was attracted north, then it corresponds to the magnet south pole.Then use a simple rule, which is that the magnetic
field lines (vector magnetic induction ) come from the north pole of the magnet and enter the south.
Determine direction vector magnetic induction live conductor.First, connect the line wire to the power supply.Do not forget that for current direction to take direction from the positive pole of the current source to the negative.Take the right-hand rule (corkscrew), or imagine that hold it in your hand.
Screw corkscrew in the direction of current in the conductor.Thus, the rotation of the handle will point direction of magnetic field lines.Draw the line and build a tangent vector.Vector construction and will show direction of the magnetic induction .
Find out where the vector is directed in induction coil with current.Also take a corkscrew (gimlet).Set it perpendicular to the plane of the coil.Gimlet rotate in the direction of the current.Translational motion and determines the spin direction lines of magnetic induction in the center of the loop.
Determine direction of the magnetic field coil and solenoid (coil conductor wound on a cylindrical surface).Use the right-hand rule.Connect the coil / solenoid to any power source, having received full closed circuit.Right hand position so that four elongated fingers pointing current direction in the turns.
lag thumb will direction vector magnetic induction inside the solenoid or coil.To not use a rule of thumb, if it seemed difficult for you, bring the magnetic needle or the solenoid coil.Blue (north) end of the arrow indicates the direction vector induction .Note that the lines of force in the solenoid - straight.