Right Hand Rule

Right Hand Rule

- The relationship between the flow of electrons and the

direction of .magnetic field

Since the velocity and magnetic field are perpendicular with each other, the thumb points to the direction of the charge, and the direction of the magnetic field is through your fingers. When you curl your fingers, it will indicate the direction of the magnetic force.

Magnitude of magnetic force

F = Bqv

Magnitude of force in Newtons

Magnetic induction in webers/meter2

Charge in Coulombs

Component of the velocity perpendicular

to B

Example

1. What is the force on an electron that moves with a speed of 106 m/sec perpendicular to a magnetic field of 0.5 weber/m2? The charge of an electron is 1.6 x 10-19 C.

Given

Speed of electron v 106 m/sec

Magnetic field B 0.5 weber/m2

Charge of an electron q 1.6 x 10-19 C

SOLUTION:

F = B v q = 0.5 weber/m2(106 m/sec )(1.6 x 10-

19 C)

P.S : 1 ampere = 1 coulomb/s = 1 C/s

F= 8 x 10 -14 N

SOLENOID

If a wire is bent into many continuous loops to form a long spiral coil, then the magnetic lines of force tend to go through the center of the coil from one end to the other rather than around the individual loops of wire. Such a coil, called a solenoid, behaves in the same way as a magnet and is the basis for all electromagnets.

Direction of magnetic field, counterclockwise

Direction of moving charge, according to the right hand crew

rule