Current carrying conductor in a magnetic field.

N S

+ -

XN S

A current carrying conductor in a magnetic field experiences a .....................The direction is given by .................... ............. . ............. Motor rule. Force

Fields in ............................... direction they cancel out/become weakened - resulting in a downward force.

Current carrying conductor in a magnetic field.

N S

+ -

XN S

A current carrying conductor in a magnetic field experiences a force.The direction is given by Flemmings Left Hand Motor rule. Force

Fields in opposite direction they cancel out/become weakened - resulting in a downward force.

Right Hand Wire Rule

A .............................. field is generated around any conductor when an electric current flows through I t.

Magnetic EffectMagnetic Effect

Electric current

Wire with current coming ...................... you Wire with current

going ............... from you

x

Magnetic EffectMagnetic Effect A magnetic field is generated around any conductor

when an electric current flows through it.

Electric current

Wire with current coming towards you Wire with current

going away from you

x

SOLENOIDSOLENOID A coil generates a very concentrated (strong)

magnetic field in its center.Electric current

x

N

S

x

x

Increasing the number of coils strengthens the magnetic field.

The .............. Hand Rule can also be applied to a solenoid!

INSIDE THE COIL THE FIELD GOES FROM ...............TO ..............!!!

Right Hand Rule - Solenoid

Solenoid Field

• Note field same as bar magnet • Inside S N!!!!!

Web Applet Demo>>

THE ELECTRIC MOTOR

• Indicate the direction of rotation with an arrow.• Show the application of the rule used to decide which way the coil

will turn.

N

current

S

+ -

C

A

B

D

C

THE ELECTRIC MOTOR

N

current

S

CurrentCurrent

Magnetic Magnetic FieldField

ThrustThrust

A

B

D

+ -

Rotation

ThrustThrust

THE MOTOR EFFECT

N S

+ -

XN S

A current carrying conductor in a magnetic field experiences a …………….The direction is given by ……………………………….. rule.

Fields in opposite direction they ………………………… ………………… - resulting in a …………………….. force.

………………..

………………....………………..

ForefingerSecond

Thumb Magnetic fields ……………………..

THE MOTOR EFFECT

N S

+ -

XN S

A current carrying conductor in a magnetic field experiences a force.The direction is given by Fleming's Left Hand Motor rule.

Force

X

Fields in opposite direction they cancel out/become weakened - resulting in a downward force.

CurrentCurrent

FieldFieldThrustThrust

ForefingerSecond

Thumb Magnetic fields strengthened!

THE ELECTRIC MOTOR

• Supply the missing labels and indicate the polarity of the battery.• Show how the direction of rotation supports your decision.

THE ELECTRIC MOTOR

- +-- ++

Electromagnetic Induction

N S

+-An electrical conductor that is accelerated through a magnetic field will experience an …………….. .electrical current according to Fleming's .................Hand Rule.

………..

..................................

..................................

........................

Forefinger

SecondThumb

Faraday’s Law

The size of the induced ……………….is directly proportional to the …………….of change of the magnetic …….. ……………….

.............. current

Electromagnetic Induction

N S

+-An electrical conductor that is accelerated through a magnetic field will experience an INDUCED electrical current according to Fleming's Right Hand Rule.

Thrust

CurrentCurrent

FieldField

ThrustThrust

Forefinger

SecondThumb

Faraday’s Law

The size of the induced current is directly proportional to the rate of change of the magnetic flux linkage.

Alternating Current• Voltage & current …………. constantly.

Alternating Current• Voltage & current vary constantly.

Coil vertical – 90o to the magnetic field

A maximum current would be produced at the same time as the maximum voltage.

V = vmax sin 2ftI = Imax sin 2ft

0o 90o 180o 270o 360o

0o

360o

90o

180o

270o

Alternating and Direct Current • What would be the equivalent constant/direct current /voltage to

give the same effect as an alternating current?

??

X

~

X

Power Transmission

Reducing the current ensures ......................................in transmission.

25 000V0,6A

0.6 A

Cable resistance 200 km 10 Ω

Voltage dropV =

Power lost =

250 000V0,06A

0.6 A

Cable resistance 200 km 10 Ω

Voltage dropV =

Power lost =

P = ...........................................

P = ..............................................

Power Transmission

Reducing the current ensures less voltage/power lost in transmission.

25 000V0,6A

0.6 A

Cable resistance 200 km 10 Ω

Voltage dropV = IR = (0,6)(10) = 6.0 V

Power lost = VI = (6)(0.6) = 3,6 W

250 000V0,06A

0.06 A

Cable resistance 200 km 10 Ω

Voltage dropV = IR = (0,06)(10) = 0.6 V

Power lost = VI = (0.6)(0.06) = 0.036 W

P = VI = (25000)(0.6) = 15 000 W

P = VI = (250000)(0.06) = 15 000 W

RECTIFIED CURRENT