Title: Current carrying conductor in a magnetic field.
1Current carrying conductor in a magnetic field.
A current carrying conductor in a magnetic field
experiences a ..................... The direction
is given by ....................
............. . ............. Motor rule.
Force
N
S
Fields in ...............................
direction they cancel out/become weakened -
resulting in a downward force.
X
2Current carrying conductor in a magnetic field.
A current carrying conductor in a magnetic field
experiences a force. The direction is given by
Flemmings Left Hand Motor rule.
Force
N
S
Fields in opposite direction they cancel
out/become weakened - resulting in a downward
force.
X
3Right Hand Wire Rule
4Magnetic Effect
- A .............................. field is
generated around any conductor when an electric
current flows through I t.
Electric current
Wire with current coming ......................
you
Wire with current going ............... from you
x
5Magnetic 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
6SOLENOID
- A coil generates a very concentrated (strong)
magnetic field in its center.
Increasing the number of coils strengthens the
magnetic field. The .............. Hand Rule can
also be applied to a solenoid!
Electric current
N
x
S
INSIDE THE COIL THE FIELD GOES FROM
...............TO ..............!!!
7SOLENOID
- A coil generates a very concentrated (strong)
magnetic field in its center.
Increasing the number of coils strengthens the
magnetic field. The Right Hand Rule can also be
applied to a solenoid!
Electric current
N
x
S
INSIDE THE COIL THE FIELD GOES FROM SOUTH TO
NORTH!!!
8Right Hand Rule - Solenoid
9Solenoid Field
- Note field same as bar magnet
- Inside S ? N!!!!!
10THE ELECTRIC MOTOR
N
S
current
B
C
A
D
-
- Indicate the direction of rotation with an arrow.
- Show the application of the rule used to decide
which way the coil will turn.
11THE ELECTRIC MOTOR
Rotation
S
N
current
B
C
Thrust
A
D
-
12THE MOTOR EFFECT
-
A current carrying conductor in a magnetic field
experiences a . The direction is given by
.. rule.
N
S
Second
Forefinger
Magnetic fields ..
Thumb
N
S
Fields in opposite direction they
- resulting in a .. force.
X
13THE MOTOR EFFECT
-
A current carrying conductor in a magnetic field
experiences a force. The direction is given by
Fleming's Left Hand Motor rule.
N
S
Second
Forefinger
Force
Magnetic fields strengthened!
Thumb
N
S
Fields in opposite direction they cancel
out/become weakened - resulting in a downward
force.
X
X
14THE ELECTRIC MOTOR
- Indicate the polarity of the battery.
- Show how the direction of rotation supports your
decision.
15THE ELECTRIC MOTOR
16(No Transcript)
17Electromagnetic Induction
-
An electrical conductor that is accelerated
through a magnetic field will experience an
.. .electrical current according to
Fleming's .................Hand Rule.
.............. current
N
S
............
Thumb
Second
.................
.................
..
Forefinger
Faradays Law The size of the induced .is
directly proportional to the .of change of
the magnetic .. .
18Electromagnetic Induction
-
An electrical conductor that is accelerated
through a magnetic field will experience an
INDUCED electrical current according to Fleming's
Right Hand Rule.
N
S
Thrust
Thumb
Second
Current
Field
Thrust
Forefinger
Faradays Law The size of the induced current is
directly proportional to the rate of change of
the magnetic flux linkage.
19Electric Field Strength
-
Magnetic field Strength (B) measured in
()
(.)
(...)
N
S
- Total number of field lines is called ..
(.) measured in . () - ? .
- ? .. ()
- B . ()
- A . through which flux passes
Thrust
(..)
? no of . in that area.
1 .. is the field . when a current of
.. A flows through a conductor and it
experiences a .. of N per meter of length.
20Electric Field Strength
-
Magnetic field Strength (B) measured in Teslas
(T)
(1A)
(1T)
N
S
- Total number of field lines is called magnetic
flux (?) measured in Webers (Wb) - ? BA
- ? magnetic flux (Wb)
- B magnetic field strength (T)
- A area through which flux passes
Thrust
(1N)
? no lines in that area
1 Tesla is the field strength when a current of 1
A flows through a conductor and it experiences a
force of 1N per meter of length.
21Faradays Law
The induced emf (.) is directly proportional to
the . of change of ..
- The induced emf can be increased by
- Increasing the
- Using
- Decreasing the . moving ..
The size of the induced is (also) directly
proportional to the . of the
...
22Faradays Law
The induced emf (?) is directly proportional to
the rate of change of flux linkage (?).
- The induced emf can be increased by
- Increasing the number of coils
- Using stronger magnets
- Decreasing the time moving faster
The size of the induced current is (also)
directly proportional to the rate of change of
the magnetic flux linkage.
23Generator - .........................
24Generator - Alternator
- Alternating current is produced.
25Generator - .......................
26Generator - dynamo
- Direct current is produced.
27Alternating Current
- Voltage current . constantly.
28Alternating Current
- Voltage current vary constantly.
Coil vertical 90o to the magnetic field
0o 90o 180o 270o 360o
V vmax sin 2?ft I Imax sin 2?ft
A maximum current would be produced at the same
time as the maximum voltage.
29Alternating and Direct Current
- What would be the equivalent constant/direct
current /voltage to give the same effect as an
alternating current?
X
X
??
30Equivalent voltage/current
31Equivalent Voltage Root Mean Squared
Vmax 2
V2
Vmax2 2
Vmax2 ave (mean)
Voltage (V)
V
Exemplar Questionsgtgt Revision Questions gtgt
- Pav VRMSIRMS or P I2RMS R
32Resistance
16.97 V
12 V
Io Vrms/R .. ..
Io Vo/R ..
V
5 ?
R Vrms /Irms . ...
R Vo/Io
Resistance can be worked out either way!
33Resistance
16.97 V
V
12 V
Irms Vrms/R 12/5 2.4 A
Vo Vrms x v2 12 x v2 16.97 V
12 V (rms)
Io Vo/R 16.97/5 3.4 A
5 ?
R Vrms /Irms 12/2.4 5 ?
R Vo/Io 16.97/3.394 5 ?
Resistance can be worked out either way!
- Pav VRMSIRMS or P I2RMS R
34Power Transmission
P ..............................................
P ...........................................
0.6 A
0.6 A
Cable resistance 200 km 10 ?
25 000V 0,6A
Cable resistance 200 km 10 ?
250 000V 0,06A
Voltage drop V Power lost
Voltage drop V Power lost
- Reducing the current ensures .....................
.................in transmission.
35Power Transmission
P VI (25000)(0.6) 15 000 W
P VI (250000)(0.06) 15 000 W
0.6 A
0.6 A
Cable resistance 200 km 10 ?
25 000V 0,6A
Cable resistance 200 km 10 ?
250 000V 0,06A
Voltage drop V IR (0,048)(10) 0.48 V Power
lost VI (0.48)(10)
4.8 W
Voltage drop V IR (0,6)(10) 60 V Power
lost VI (60)(10)
600 W
- Reducing the current ensures less voltage/power
lost in transmission.
36RECTIFIED CURRENT