8.4 force on a current-carrying conductor in magnetic field

8/6/2019 8.4 Force on a Current-Carrying Conductor in Magnetic Field

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8.4 Force on

a Current-carryingconductor in

magneticField

Shahid

Mukhlis.A.G

Form 5



Catapult Force

}When a current-carrying

conductor is placed in a magnetic

field, the interaction between the two

magnetic fields will produce aforce on the conductor, which called

a catapult force



Fleming's Left

Hand Rule (Motor Rule)

The direction of the force can be

determined by Fleming's left

hand rule

The fore finger, middle finger and the thumb areperpendicularly to each other. The forefinger points

along the direction of the magnetic field,middle

finger points in the current direction and

the thumb points along the direction of the force.



Strength of the Catapult Force

The strength of the force can be

increased by:

� Increase the current� Using a stronger magnet



The Catapult Field

The interaction of the two magnetic fields (the magneticfield of the current-carrying wire and the magnetic

field of the permanent magnet) produces a resultant

field known as catapult field as shown in the figure

above.

The non-uniform field produces

the catapult force from the

stronger field to the weaker

field.



Force between

2 current carrying conductor When 2 current carrying conductors

are placed close to each other , a

force will be generated between them.

If the current in both conductors flow in

the same direction, they will attract

each other , whereas if the currents are

in opposite direction, they will repel

each other .



- How it's

produced and the field pattern?

This force is due to the interaction between

themagnetic field of the 2 conductor . The figureabove shows the catapult field produced by 2 current

carrying conductors when their current is in the same

direction or opposite direction.



Turning

of a Current-carrying Coil in aMagnetic Field



} If a current carrying coil is

placed in a magnetic field,

a pair of forces will be

produced on the coil.T

hisis due to the interaction of

the magnetic field of the

permanent magnet and

the magnetic filed of thecurrent carrying coil.



Direct Current Motor Electric motor

converts electrical

energy to kinetic

energy. It consist

a rectangular coil

of wire placed

between 2permanent

magnets. The coil

are soldered to a

copper split ring

known ascommutator. 2

carbon brushes

are held against

the commutator.

The function of

the commutator is to change

the direction of the current in

the coil and hence change the

direction of the couple (the 2

forces in opposite direction) in

every half revolution. This is to

make sure that the coil

can rotate continuously.

8.4 force on a current-carrying conductor in magnetic field

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