basic electricity basic electricity basic electricity

ppt

1. ELECTRICITY
Value of mains
supply = 230V

2. ELECTRICITY
Fuse is used as a
safety device
Prevents too much
current flowing in
circuit.

3. ELECTRICITY
Power of
appliances
measured in
watts (W)

4. ELECTRICITY
Plug wires –colours
Live –brown
Neutral –blue
Earth –green/yellow
Fuse in live position

5. ELECTRICITY
Double insulation –no earth
wire required as casing of
appliance is plastic –non
conductor

6. ELECTRICITY
Human being is a conductor
of electricity so do not touch
wires ,do not come into
contact with water with
electricity.

7. Electricity
PARTS OF THE RADIO
1. AERIAL -PICKS UP ALL
SIGNALS
2. TUNER –SELECTS ONE
PARTICULAR SIGNAL

8. TELECOM
3.DECODER –SEPARATES
CARRIER WAVE FROM
AUDIO WAVE
4. AMPLIFIER –MAKES
BIGGER COPY OF AUDIO
WAVE

9. TELECOM
5. BATTERY –SUPPLIES
ENERGY TO AMPLIFIER
6. LOUDSPEAKER –
CHANGES ELECTRICAL
ENERGY TO SOUND
ENERGY

10. TELECOM
COLOUR MIXING
3 PRIMARY COLOURS –
RED , GREEN , BLUE
TOGETHER MAKE WHITE

11. TELECOM
RED AND GREEN GIVE
YELLOW.
RED AND BLUE GIVE
MAGENTA
GREEN AND BLUE GIVE
CYAN

12. TELECOM
GEOSTATIONARY
SATELLITES ARE AT A
HEIGHT OF 36 , 000Km
ABOVE THE EARTH
THEY HAVE A 24 HR ORBIT

13. TELECOM
SIGNALS ARE MICROWAVE
AND TRAVEL IN A
STRAIGHT LINE TO AND
FROM THE SATELLITE.THEY
CANNOT CURVE IN THE
EARTH`S ATMOSPHERE

14. TELECOM
OPTICAL FIBRES USED TO
CARRY INFORMATION BY
TOTAL INTERNAL
REFLECTION. LIGHT
TRAVELS AT A SPEED OF
200 , 000 , 000 M/S

15. ELECTRICITY
EQUATIONS
Q = I x TV = I x R
P = I x VP = E / t
P = V
2
/ RP = I
2
R
R
T= R
1 + R
2
1 /R
T= 1/R
1+ 1/R
2

16. ELECTRICITY
RULES FOR SERIES AND PARALLEL CIRCUITS
VOLTAGE SPLITS UP IN A SERIES CIRCUIT
CURRENT STAYS THE SAME IN A SERIES
CIRCUIT
VOLTAGE STAYS THE SAME IN A PARALLEL
CIRCUIT
CURRENT SPLITS UP IN A PARALLEL CIRCUIT

17. ELECTRICITY
VOLTMETERS MEASURE VOLTAGE AND
GO ACROSS THE COMPONENT
AMMETERS MEASURE CURRENT AND ARE
WIRED IN SERIES WITH THE
COMPONENTS.
CIRCUIT COMPONENTS INCLUDE
RESISTORS , BULBS ETC.

18. ELECTRICITY
MAINS ELECTRICITY
WIRES IN THREE PIN PLUG
1.BROWN LIVE 2. BLUE NEUTRAL
3. GREEN / YELLOW EARTH
FUSE IS A SAFETY DEVICE WIRED IN THE
LIVE PIN
EARTH WIRE NOT NEEDED FOR DOUBLE
INSULATED APPLIANCES , THEY HAVE A
PLASTIC CASING

19. ELECTRICITY
MAINS ELECTRICITY
THREE TYPES OF CIRCUIT
1. THE LIGHTING CIRCUIT 15A FUSE2.
THE RING MAINS CIRCUIT 30A FUSE
3.THE COOKER CIRCUIT 45A FUSE
ALL ARE WIRED IN PARALLEL IF ONE
GOES OUT THE OTHERS STAY ON LESS
WIRE USED SO MONEY IS SAVED

20. ELECTRICITY
ELECTRIC MOTORS
COIL OF WIRE CARRYING CURRENT
SURROUNDED BY A PAIR OF MAGNETS
THE MORE TURNS ON THE COIL AND THE
STRONGER THE MAGNET , THE FASTER
THE COIL GOES.

21. ELECTRICITY
TWO COILS OF WIRE WITH AN IRON
CORE , THE PRIMARY COIL AND THE
SECONDARY COIL
TRANSFORMERS
N
P/N
S= V
P/ V
S
I
Px V
P= I
Sx V
S

22. HEALTH
TYPES OF THERMOMETER
1. THE LAB THERMOMETER2. THE
CLINICAL THERMOMETER BOTH LIQUID
IN GLASS THERMOMETERS 3. THE
DIGITAL THERMOMETER
DIFFERENCE BETWEEN LAB AND
CLINICAL THERMOMETERS, SIZE,SCALE,
MAGNIFIER IN CLINICAL
THERMOMETER,KINK