Any conductors with current, moving charged particles, magnets create magnetic field around. Having defined the direction of magnetic lines, it is possible to find out how it will influence the loaded objects which are nearby.
It is required to you
- - current source (conductor, solenoid);
- - right hand;
- - magnetic needles.
Instruction
1. To learn the direction of magnetic lines for the direct conductor with current, arrange it so that electric current went in the direction from you (for example, in the sheet of paper). Try to remember how the drill or the screw twisted by the screw-driver moves: clockwise and forward. Represent this movement by a hand to understand the direction of lines. Thus, lines of magnetic field are directed clockwise. Note them schematically on the drawing. This method is called the rule of the gimlet.
2. If the conductor is located not in that direction, mentally get up thus or turn a design so that current moved away from you. Then remember the movement of a drill or the screw and put the direction of magnetic lines clockwise.
3. If the rule of the gimlet seems to you difficult, try to use the rule of the right hand. That with its help to define the direction of magnetic lines, arrange a hand use the right hand with the bulged thumb. Direct a thumb on the movement of the conductor, and 4 other fingers – in the direction of induction current. Now pay attention, power lines of magnetic field are included into your palm.
4. To use the rule of the right hand for the coil with current, clasp it mentally with a palm of the right hand so that fingers were directed along current in rounds. Look where watches the set aside thumb - it is and there is a direction of magnetic lines in the solenoid. This way will help to define orientation of a metal pig if you need to load a magnet by means of the coil with current.
5. To define the direction of magnetic lines by means of a magnetic needle, arrange several such arrows around a wire or the coil. You will see that axes of arrows are directed on tangents to a circle. By means of this method it is possible to find the direction of lines in each point of space and to prove their continuity.