The bending force is computed by the vector cross product. Because the charge is moving, the force causes the particle path to bend. If the curl of the right fingers represents a rotation from the direction the charge is moving to the direction of the magnetic field then the force is in the direction of the right thumb.
If the fingers of the right hand are curled in the direction of the circular component of the current, the right thumb points to the north pole. The + z end where the lines exit is defined as the north pole. Since there is no magnetic monopole, the field lines exit the + z end, loop around outside the helix, and reenter at the − z end. The advance of the helix, the non-circular part of the current and the field lines all point in the positive z direction. If the wire is coiled into a helix all the field lines inside the helix point in the same direction and each successive coil reinforces the others.
The conventional direction of a magnetic line is given by a compass needle. The conventional current, which is the opposite of the actual flow of electrons, is a flow of positive charges along the positive z axis. When electricity ( conventional current) flows in a long straight wire it creates a circular or cylindrical magnetic field around the wire according to the right-hand rule.The rule is this: if a screw is right-handed (most screws are) point your right thumb in the direction you want the screw to go and turn the screw in the direction of your curled right fingers. The threads of a screw are a helix and therefore screws can be right- or left-handed. Helices are either right- or left-handed, curled fingers giving the direction of rotation and thumb giving the direction of advance along the z axis. Rotations A rotating body Ī helix is a curved line formed by a point rotating around a center while the center moves up or down the z axis. (If the axes do not have a positive or negative direction then handedness has no meaning.) Reversing two axes amounts to a 180° rotation around the remaining axis. Reversing the direction of one axis (or of all three axes) also reverses the handedness. Interchanging the labels of any two axes reverses the handedness. When viewed from the top or z axis the system is clockwise. When viewed from the top or z axis the system is counter-clockwise.įor left-handed coordinates the left thumb points along the z axis in the positive direction and the curled fingers of the left hand represent a motion from the first or x axis to the second or y axis.
#REFLECT ACROSS Y AXIS SERIES#
Thumb, then index finger, then middle (e.g., see the ninth series of the Swiss 200-francs banknote).įor right-handed coordinates use right hand.įor left-handed coordinates use left hand.įor right-handed coordinates the right thumb points along the z axis in the positive direction and the curl of the fingers represents a motion from the first or x axis to the second or y axis.Middle finger, then thumb, then index finger.However, two other sequences also work because they preserve the cycle: The sequence is often: index finger, then middle, then thumb. The rule can be used to find the direction of the magnetic field, rotation, spirals, electromagnetic fields, mirror images, and enantiomers in mathematics and chemistry.
Left-hand and right-hand rules arise when dealing with coordinate axes. The curl of the fingers represents a movement from the first ( x axis) to the second ( y axis), then the third ( z axis) can point along either thumb. One can see this by holding one's hands outward and together, palms up, with the fingers curled, and the thumb out-stretched. Most of the various left-hand and right-hand rules arise from the fact that the three axes of three-dimensional space have two possible orientations. In mathematics and physics, the right-hand rule is a common mnemonic for understanding orientation of axes in three-dimensional space. Finding the direction of the cross product by the right-hand rule
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