Term
| What happens when an electric current passes through a wire? |
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Definition
| A magnetic field is produced. |
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Term
| How can you make an electomagnetic magnet stronger? |
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Definition
1. Add an iron core
2. Increase the current
3. Increase the number of turns of wire |
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Term
| Name some uses of electromagnets. |
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Definition
Crane - Able to pick up rubbish, move it and drop it because the magnet can be turned on and off.
Circuit breaker - If the current in the live wire increases due to a fault, the strength of the electromagnet does too. If the current becomes too high, the electromagnet will pull the switch open and break the circuit.
An electric bell - Current goes into the electromagnet increasing the strength of the magnetic field, pulling the make & break switch, disconnecting the circuit, stopping the electromagnet, letting go of the switch and reconnecting the circuit again.
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Term
| Name some uses of electromagnets. |
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Definition
Crane - Able to pick up rubbish, move it and drop it because the magnet can be turned on and off.
Circuit breaker - If the current in the live wire increases due to a fault, the strength of the electromagnet does too. If the current becomes too high, the electromagnet will pull the switch open and break the circuit.
An electric bell - Current goes into the electromagnet increasing the strength of the magnetic field, pulling the make & break switch, disconnecting the circuit, stopping the electromagnet, letting go of the switch and reconnecting the circuit again.
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Term
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Definition
| Circular Motion is where the velocity (speed and direction of an object) is constantly changing, in other words turning in a circle. |
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Term
| What three Resultant Forces act on an object towards the centre of the circle which cause acceleration? |
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Definition
1. Tension
2. Friction
3. Gravity |
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Term
Complete the sentence
'The faster an object's moving, the ______ the centripetal force has to be to keep it moving in a circle.'
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Definition
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Term
Complete the sentence
'The larger the mass of an object, the ______ the centripetal force has to be to keep it moving in a circle.' |
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Definition
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Term
Complete the sentence
'The smaller the circle, the ______ the centripetal force has to be to keep an object moving in a circle.' |
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Definition
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Term
| What force is providing the Centripetal Force in a car going round a bend? |
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Definition
| The friction between the car's tyres and the road. |
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Term
| What force is providing the Centripetal Force in a car going round a bend? |
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Definition
| The friction between the car's tyres and the road. |
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Term
| What are Switch Mode Transformers? |
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Definition
| A type of transformer that operate at higher frequencies than traditional transformers. |
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Term
| What frequency do Switch Mode Transformers usually operate between? |
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Definition
| Between 50kHz and 200kHz. |
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Term
| Name the main advantage of Switch Mode Transformers. |
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Definition
| Because they work at higher frequencies, they can be made much lighter and smaller so are useful in things like moblie phone chargers and laptop power supplies. |
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Term
| In Step-Up Transformers, are there more turns on the Primary or Secondary Coil? |
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Definition
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Term
In Step-Down Transformers, are there more turns on the Primary or Secondary Coil? |
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Definition
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Term
| Why is there an Alternating Current (AC) in the Secondary Coil? |
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Definition
| Because there is an AC in the primary coil, the field in the iron core is constantly changing direction (changing magnetic field). This rapidly changing magnetic field is then felt by the secondary coil. This changing field induces an alternating potential difference in the secondary coil. |
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Term
| Does the Iron Core carry the Current or the Magnetic Field? |
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Definition
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Term
| Do Transformers work with an Alternating Current (AC) or a Direct Current (DC)? |
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Definition
| Alternating Current (AC). |
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Term
| What is Electromagnetic Induction? |
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Definition
| The creation of a potential difference across a conductor which is experiencing a change in magnetic field. |
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