How to determine the direction of magnetic induction vector

Determine the direction of the vector of induction in the field of the permanent magnet. First, locate the North and South poles in the magnet — North is usually colored blue and marked with the letter N, and the southern painted red and put the letter S. If the paint and markings on the magnet not, determine the pole using the magnetic needle of known poles.

Select the arrow next to the magnet to one end of the arrow pulled to him. If the magnet attracted the South pole of the arrow on the magnet is the North pole. If, on the contrary, pulled North on the magnet it corresponds to the South pole. Then use a simple rule, which is that the magnetic field lines (the vector of magnetic induction) out of the North pole of a magnet and enter the South.

Determine the direction of the vector of magnetic induction in a straight conductor. First, connect direct wire to the current source. Don't forget that the direction of current need to take direction from the positive pole of the current source to the negative. Take the right gimlet (corkscrew) or imagine that you're holding in your hand.

Screw the corkscrew in the direction of the current in the conductor. Therefore, the rotation of the handle will indicate the direction of the magnetic field lines. Sketch the line and build a tangent vector. The constructed vector will show the direction of magnetic induction.

Find out where is the vector of the induction in the coil with current. Also take the corkscrew (the corkscrew). Install it perpendicular to the plane of the loop. Rotate the thumb in the direction of the current. The translational motion of the spin determines the direction of lines of magnetic induction in the center of the loop.

Determine the direction of the magnetic field for the coil and solenoid (coil conductor wound on the cylindrical surface). Use the right hand rule. Connect the coil/solenoid to any power source, once a closed circuit. Right hand position so that the four elongated fingers indicate the direction of current in the coils.

Set aside the thumb will show the direction of the vector of magnetic induction inside the solenoid or coil. To not use right-hand rule, if it seemed to you difficult, bring a magnetic needle to the solenoid or coil. Blue (North) end of the arrow indicate the direction of the vector of induction. Please note that the lines of force in the solenoid — direct.