IGCSE Physics- Electricity and Magnetism 5.0 / 5 based on 1 rating ? PhysicsElectricityMagnetismIGCSEEdexcel Created by: orielegriggCreated on: 22-04-16 20:59 What metals can a permanent magnet be made out of? Iron, Nickel, Cobalt (and Steel) 1 of 33 If these metals have not been turned into magnets but are in the magnetic field of a magnet, will they be attracted to it? Yes 2 of 33 What is this called? Induced magnetism 3 of 33 You can only prove an object is a magnet if it _______ another magnet You can only prove an object is a magnet if it repels another magnet 4 of 33 In which direction do the magnetic field lines go? North to South or South to North? NORTH to SOUTH 5 of 33 When an electric current flows in a wire it creates what around the wire? A magnetic field 6 of 33 How do you make an electromagnet stronger? (3 points) 1. More turns in the coil, 2. Wrapping the wire around and iron core, 3. Increasing the current in the coil 7 of 33 What is a relay? An electrically operated switch 8 of 33 Voltage is produced when a magnet moves inside a coil of wire, what is this called? Electromagnetic induction 9 of 33 How do you increase electromagnetic induction? (3 points) 1. Add more turns to the coil, 2. Increase the strength of the magnet, 3. Move the magnet faster 10 of 33 What is a simple electric motor made of? A coil of wire that can move between two opposite poles (magnets) 11 of 33 Why must the direction of the current be reversed every half turn? Otherwise the coil of wire wouldn't turn any further 12 of 33 What part of the motor is responsible for this? Split ring/commutator 13 of 33 How does a generator induce a current? (with a magnet and a coil of wire) By spinning a magnet inside a coil of wire 14 of 33 How does a bicycle dynamo work? The dynamo has a wheel that touches the back tyre. As the bicycle moves, the wheel turns a magnet inside a coil. 15 of 33 When do you use Fleming's left hand rule and when do you use Fleming's right hand rule? Left: motors, Right: generators 16 of 33 thuMb is for? Movement 17 of 33 Forefinger is for? Field (North to South) 18 of 33 seCond finger is for? Current (+ to -) 19 of 33 Does a generator produce AC or DC? AC because as the magnet/coil is rotated, the direction of the current is reversed EVERY HALF TURN 20 of 33 The size of the induced voltage can be increased by: (3 points) 1. Rotating the magnet/coil faster, 2. Using a stronger magnet, 3. More turns in the coil 21 of 33 Is mains current AC or DC? AC and 230V 22 of 33 Transformers are used to increase/decrease what? e.g. current...voltage Voltage 23 of 33 A transformer consists of ___ coils of wire around a metal ____ A transformer consists of TWO coils of wire around a metal CORE 24 of 33 If the PRIMARY coil has more turns than the SECONDARY coil, is the voltage being increased or reduced? Reduced 25 of 33 When a _______ flows through a wire some energy is lost as ____. When a CURRENT flows through a wire some energy is lost as HEAT 26 of 33 To reduce the _______ (and therefore the heat loss) the National Grid transmits __________ at a low _______ To reduce the CURRENT (and therefore the heat loss) the National Grid transmits ELECTRICITY at a low CURRENT 27 of 33 How do they lower the current? and what device do they use? Increase the voltage using a step-up transformer 28 of 33 What is an equation that links electrical power, voltage and current? (elecrtical) power = voltage x current 29 of 33 Dangers of UV? Cancer, UV burns, blindness 30 of 33 Dangers of infrared? Burns 31 of 33 Dangers of microwaves? Internal heating of body tissues 32 of 33 Dangers of BOTH X-rays and Gamma rays? Cell mutation, Cancer, Kills cells 33 of 33
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