Electromagnets And Materials Flashcards
What is chemical energy
Chemical energy is released form materials when chemical reactions take place.
What is nuclear energy
It is released from the nucleus of an atom through radioactivity or nuclear fusion
What is the law of energy conservation
Energy can not be created, only transferred of wasted
What are the energy pathways
-mechanical
(A force moving an object)
-electrical
(Charges moving in a circuit)
-Heating
(A temperature difference)
-Radiation
(Transfer by a wave, light or infared)
Is potential difference and voltage the same thing?
Yes they are the same.
What is current described as?
It is described as the flow of electrons
What stops a circuit from working
If there is a break in the circuit
“Cu rent splits across loops in a parallel circuit but stays the same in a se ies circuits” is the description of what?
It is the description of how the current flows in circuits.
What is an independent variable?
The thing we change.
What is the dependant variable?
The thing you measure.
What is the control variable?
The things you keep the same.
What is the definition of power in science?
Power is the rate at which energy is transferred
What are the units of power?
Watts and kilowatts (1000 watts)
What calculation is used to calculate energy use?
Energy Transferred = Power x Time
What is energy measured in?
Joules ( J )
What happens When an electric current passes through a wire?
a magnetic field is
created.
What is a loop of wire called?
A solenoid
Are electromagnets the same as bar magnets?
Yes an electromagnet acts like a bar magnet when it has an electric
current flowing through it, but a bar magnet cant turn off while a electromagnet can.
When cu rent flows through a wire,does it generate a magnetic field
Yes
What are 3 strengths of an electromagnet.
- the strength can be changed
-It can be switched off.
-It can be reversed.
What happens when a soft iron core is added to an electromagnet?
It gets stronger.
Do motors and loudspeakers use the same effect to work?
Yes they do.
What happens in an electrical motor if the current is reversed
The rotation will reverse
What will happen in the motor if the flow is reversed and the permanent magnet is reversed?
Nothing will change .
What would decrease the strength of an electromagnet
Adding a plastic core
What part of a loudspeaker causes the air to vibrate
The cone
Do microphones work the same way as loudspeakers
No
What is a compound
2 or more different elements joined together by chemical. Bonds
What is an element
A substance containing just one atom type
What is the term native?
It is an element found in a rock in its pure state
What is a yield
It is the percentage of an amount of useful substance in a product
What is an oxide reaction
A chemical reaction involving the addition of of oxygen
Where are elements found?
In the earths crust
What is a rock labelled as if they have not reacted to the air?
Native/pure
What do they form when they react with the air
They form compounds
