Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
17 Cards in this Set
- Front
- Back
|
What is current? |
A current is the flow of electric charge. |
|
|
What is current measured in? |
Current is measured in ampere, Amps. |
|
|
How can we measure current in a circuit? |
Just put an ammeter in the circuit. |
|
|
If it says 1amp is in a circuit, what does it mean? |
1amp means there is 1 coulomb passing every second at one point of the circuit. |
|
|
What does a coulomb mean? |
A coulomb is a certain amount of electrical charge. 6.24 x 10^18 electrons = 1 coulomb |
|
|
So summarise what a current is. |
A current is a flow of charge that is measured in amps by an ammeter which means the amount of coulombs passing a second. For an answer in exams: A current is a flow of charge in a circuit. |
|
|
Now, what is Potential Difference? |
Potential difference is the amount of work done per coulomb, also known as voltage, is the "push" that moves the current around the circuit. It's the pushing force for the current. |
|
|
What can we use to produce a Potential difference? |
We can use a battery to create potential difference. |
|
|
What is Potential Difference measured in? |
Potential difference is measured in Volts, ( V ) |
|
|
How can we measure the Potential difference between a certain component? |
We use a voltmeter that connects to the two ends of the component |
|
|
If a component has 1 volts, what does it mean? |
It means the amount of work ( J ) that can be completed for every 1 per of coulomb. Work done means energy transferred into the component. So 1 volts means 1 Joules of work being transferred for every coulomb. |
|
|
The work done on a lamp in a circuit is 20 J when 5 C of charge pass through.
What is the Potential Difference?
V= W/Q |
20 J of energy transferred into the lamp for every 5 coulombs.
V=W/Q V=20J / 5C V= 4 4V |
|
|
What is resistance? |
Resistance tells us how difficualt it is for electrons to pass though a component. |
|
|
What is resistance measured in? |
We measure resistance in Ohms (n) |
|
|
What does a resistor do? |
Resistoer are puposly built so that it requires alot of energy to pass though the restitoer They would get hot as they pass through. |
|
|
What is the relationship between resistance and current? |
The greater the resistance, the smaller the current that flows So this means a lot of electrons are being slowed down. |
|
|
What is the Relationship between Potential Difference and Current through a resistor? |
Potential difference is directly proportional to current. So as Potential difference increase, the current increase. Only if the temperature is the same though out |
