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KS3Electr&Magnet
Question | Answer |
---|---|
State the law of magnetism | Opposite poles attract and like poles repel. |
State the objects that make an electro-magnet | Nail, Coil of wire, Power pack, Leads, Crocodile clips, Paper clips. |
Suggest a way to make an electro-magnet stronger | You can increase the number of turns with the wire or increase CURRENT or use a soft iron core |
Explain why the filament in a bulb snaps when it gets used a lot or left on | The filament is really small; this prevents the current from flowing freely=ie there is a resistance. The filament snaps because t gets very hot so it melts and snaps. |
Explain how the current flows in a parallel circuit | The current can choose a path through the wire. |
Define an electromagnet? | a electro magnet is the passage of electric current through a coil surrounding it. It is a magnet that can be turned on and off. |
What is the difference between a series circuit and a parallel circuit? (Compare teh two circuits) | the difference is that in a series circuit the voltage is split by the number of light bulbs, but in a parallel circuit the voltage is the same for each loop but the currents split is shared |
Predict whether two South poles put together attract, or repel | repel |
Describe how a compass work | the core of the earth is a magnet, and so is a compass. The compass always points north because the South pole of teh compass is attracted to teh North pole of the Earth follow. |
Predict what happens when a magnet is near a compass? | the compass points towards the magnet because the magnetic field is nearer and stronger, and because a compass is a magnet itself, it is attracted. |
Define an electrical current? | Flow of electrons |
Predict what happens to the resistance in a smaller wire? | The resistance increases |
In a circuit with 4 light bulbs and to batteries predict if the light bulbs be bright or dim? | A Dim. |
Explain why metals is a conductor? | Because metals let electrons flow through them. |
Explain why in a bigger wire the electrons flow easily? | because there is more space to flow in. |
Explain what happens when too much electrons flow (ie a too high current) through a fuse (wire)? | A the fuse gets real hot and may snap. |
What is a volt? | a volt is the measure of how strongly the battery pushes the electron; a measure of the energy. |
Explain why can’t electricity go throw a broken CIRCUIT why? | ELECTRONS CAN NOT GO THROUGH THE GAP, back to teh other side of the battery |
State what is current measured in? | In amps by an ammeter. |
Define an insulator? | an insulator does not let any electricity through e.g a wooden spoon |
If I was to put two iron nail into a fruit to make a fruit battery, would it work? | No, you need two DIFFERENT metals |
If I put three bulbs onto a series circuit predict what happens to the brightnessand explain your answer. | dimmer as the energy would have to be shared. |
Describe how to make a fruit battery? | Take two pieces of DIFFERENT metals and place them on either side of the fruit, after that place connect the wire from one end of the volt meter to the first metal and connect the second wire from the other end of the voltmeter to the second metal. |
Name the two metals that would give the fruit battery the highest voltage. Explain your choice | Magnesium and copper, because they are far apart in the reactivity series |
Describe how does the current change as you add more bulbs | The current will decrease as the resistance in the circuit increases. |
Predict what will happen to the bulbs in a series circuit if one bulb blows. Explain your answer | the other bulbs will go out, because the circuit is broken |
State what materials are attracted to magnets | Magnets attract Iron (Steel), Cobalt and Nickel. |
Explain why do we put batteries in a circuit? | To provide the energy for the bulbs in the same circuit. |