p20 - ELECTRICITY ELECTRICITY Value of mains supply = 230V...

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Unformatted text preview: ELECTRICITY ELECTRICITY Value of mains supply = 230V ELECTRICITY ELECTRICITY Fuse is used as a safety device Prevents too much current flowing in circuit. ELECTRICITY ELECTRICITY Power of appliances measured in watts (W) ELECTRICITY ELECTRICITY Plug wires – colours Live – brown Neutral – blue Earth – green/yellow Fuse in live position ELECTRICITY ELECTRICITY Double insulation – no earth wire required as casing of appliance is plastic –non conductor ELECTRICITY ELECTRICITY Human being is a conductor of electricity so do not touch wires ,do not come into contact with water with electricity. Electricity Electricity 1. AERIAL ­ PICKS UP ALL PARTS OF THE RADIO SIGNALS 2. TUNER – SELECTS ONE PARTICULAR SIGNAL TELECOM TELECOM SEPARATES CARRIER WAVE FROM AUDIO WAVE 4. AMPLIFIER – MAKES BIGGER COPY OF AUDIO WAVE 3. DECODER – TELECOM TELECOM 5. BATTERY – SUPPLIES ENERGY TO AMPLIFIER 6. LOUDSPEAKER – CHANGES ELECTRICAL ENERGY TO SOUND ENERGY TELECOM TELECOM 3 PRIMARY COLOURS – COLOUR MIXING RED , GREEN , BLUE TOGETHER MAKE WHITE TELECOM TELECOM YELLOW. RED AND BLUE GIVE MAGENTA GREEN AND BLUE GIVE CYAN RED AND GREEN GIVE TELECOM TELECOM SATELLITES ARE AT A HEIGHT OF 36 , 000Km ABOVE THE EARTH THEY HAVE A 24 HR ORBIT GEOSTATIONARY TELECOM TELECOM SIGNALS ARE MICROWAVE AND TRAVEL IN A STRAIGHT LINE TO AND FROM THE SATELLITE.THEY CANNOT CURVE IN THE EARTH`S ATMOSPHERE TELECOM TELECOM TO CARRY INFORMATION BY TOTAL INTERNAL REFLECTION. LIGHT TRAVELS AT A SPEED OF 200 , 000 , 000 M/S OPTICAL FIBRES USED ELECTRICITY ELECTRICITY EQUATIONS Q = I x T P = I x V RT = R1 + R2 P = V2 / R V = I x R P = E / t P = I2R 1 /RT = 1/R1 + 1/R2 ELECTRICITY 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 ELECTRICITY ELECTRICITY AND GO ACROSS THE COMPONENT AMMETERS MEASURE CURRENT AND ARE WIRED IN SERIES WITH THE COMPONENTS. CIRCUIT COMPONENTS INCLUDE RESISTORS , BULBS ETC. VOLTMETERS MEASURE VOLTAGE ELECTRICITY 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 ELECTRICITY ELECTRICITY THREE TYPES OF CIRCUIT MAINS ELECTRICITY 2. 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 1. THE LIGHTING CIRCUIT 15A FUSE ELECTRICITY ELECTRICITY SURROUNDED BY A PAIR OF MAGNETS THE MORE TURNS ON THE COIL AND THE STRONGER THE MAGNET , THE FASTER THE COIL GOES. COIL OF WIRE CARRYING CURRENT ELECTRIC MOTORS ELECTRICITY ELECTRICITY TWO COILS OF WIRE WITH AN IRON CORE , THE PRIMARY COIL AND THE SECONDARY COIL TRANSFORMERS NP /NS = VP / VS IP x VP = IS x VS HEALTH HEALTH 1. THE LAB THERMOMETER 2. 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 TYPES OF THERMOMETER ...
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