What is the direction of Lorentz force
Flatten the left palm and let the magnetic line of force pass through the palm. The four fingers indicate the direction of the positive charge, and the direction of the thumb perpendicular to the four fingers is the direction of the Lorentz force. However, it should be noted that the moving charge is positive, and the direction of thumb is the direction of Lorentz force
the direction of Lorentz force is always perpendicular to the direction of particle motion, Lorentz force only changes the direction of velocity, does not change the size of velocity, so Lorentz force will never have an integral with V, that is, Lorentz force will never do work
extended data:
ampere force is f = ILB, Lorentz force is f = QVB. Although the expressions of Ampere force and Lorentz force are different, they can be deced and confirmed by each other. Lorentz force is a microcosmic form and Ampere force is a macroscopic one. Lorentz force is the force exerted on a single moving charge in a magnetic field, while ampere force is the macroscopic expression of Lorentz force exerted on all directional moving free charges in a conctor
Although ampere force is the macroscopic expression of Lorentz force on all directionally moving free charges in a conctor, it can not be considered that ampere force is simply equal to the sum of Lorentz forces on all directionally moving charges, which can only be considered when the conctor is at rest1 the magnetic inction line passes through the palm
2 the four fingers point to the direction of motion
3 the thumb is the direction of force
Flatten the left palm, let the magnetic inction line pass through the palm, four fingers indicate the direction of positive charge movement, then the direction of thumb perpendicular to four fingers is the direction of Lorentz force. However, it should be noted that the moving charge is positive, and the direction of thumb is the direction of Lorentz force. On the contrary, if the moving charge is negative and the direction of charge motion is still represented by four fingers, then the opposite direction of thumb is the direction of Lorentz force
another way to apply left-handed rule to negative charge is to think that negative charge is equivalent to positive charge in reverse motion, and use four fingers to indicate the opposite direction of negative charge motion, then the thumb points to the direction of Lorentz force
Electric field force: the force direction is the same as that of positive charge, but opposite to that of negative charge. Another way to judge is the tangent direction of the electric field line
Ampere force: left hand rule, stretch out your left hand and make your thumb perpendicular to the other four fingers. Let the magnetic wire pass through your palm, four fingers pointing to the direction of current, thumb pointing to the direction of Ampere forceLorentz force: left hand rule, extend your left hand so that the thumb is perpendicular to the other four fingers. Let the magnetic inction line pass through the palm of your hand, with four fingers pointing in the direction of the positive charge (or the opposite direction of the negative charge). The thumb points in the direction of Lorentz force
extended data:
Lorentz force formula, Maxwell equations and dielectric equations form the basis of classical electrodynamics. In many scientific instruments and instrial equipment, such as β Lorentz force is widely used in spectrometer, mass spectrometer, particle accelerator, electron microscope, magnetic mirror device and Hall device. It is worth noting that since ampere force is the macroscopic representation of Lorentz force, Lorentz force does not work on moving charges
In fact, Lorentz force plays the role of transferring energy. When the wire moves, part of the Lorentz force points to the opposite direction of the charge movement, which hinders the charge movement from doing negative work and forms the motional electromotive force; The other part is composed of Ampere force, which does positive work on the current carrying wire. As a result, the balance motion still generates electromotive force, and the power supply that maintains the current provides energybecause [I don't know if there is any explanation in your book]: the direction of four fingers is the direction of positive ion motion
so no matter what, the force is the same
well received
left hand rule
flatten the left palm, let the magnetic line of force pass through the palm, four fingers indicate the direction of positive charge movement, then the direction of thumb perpendicular to four fingers is the direction of Lorentz force. However, it should be noted that the moving charge is positive, and the direction of thumb is the direction of Lorentz force. On the contrary, if the moving charge is negative and the direction of charge motion is still represented by four fingers, then the opposite direction of thumb is the direction of Lorentz force
another way to apply left-handed rule to negative charge is to think that negative charge is equivalent to positive charge in reverse motion, and use four fingers to indicate the opposite direction of negative charge motion, then the thumb points to the direction of Lorentz force.