10 Electricity Flashcards
What is an electrical current?
A flow of charge.
What is the symbol for charge?
Q
What is the symbol for current?
I
What does the Q for charge stand for?
Quantity
What does the I for current stand for?
Intensity
What are electrons?
Fundamental particles with an approximate diameter of 10-¹⁸m.
What are electrons and ions called?
Electron carriers
What is charge measured in?
Coulombs (C).
What charge are electrons?
Negative
What is the definition of current?
A current of 1 ampere (1A) means that 1 coulomb (1C) of electrons flows past any point in the circuit every circuit.
What is 1A equal to?
1 C s‐¹
What is electrical current measured in?
Ampere
In which direction do electrons flow in a circuit?
From positive to negative
In a cell, which side is negative?
The short side
In a cell, which side is positive?
The long side
What are circuit rules for current?
- The current leaving the power supply is equal to the current returning to the power supply.
- The current entering a component is equal to the current leaving a component.
- Components in series have the same current flowing through them.
- The total current entering a junction is equal to the total current leaving a junction.
What happens to current as it goes through a junction?
It splits.
What is charge always?
Conserved
Explain how charge is conserved?
The number of coulombs of electrons leaving the power supply every second is equal to the number returning every second.
Where does chemical action inside a cell move electrons?
From one terminal to the other.
What is potential difference?
If the potential difference between the two points in the circuit is 1 volt then 1 joule of potential energy is lost per coulomb of electrons as they pass between those points.
What is 1V equal to?
1 J C‐¹
What is the definition of potential difference?
Energy change per unit charge.
What is used to measure potential difference?
A voltmeter
What is used to measure current?
Ammeter
What are the circuit voltage rules?
- The pd’s across components in parallel are the same
- The pd’s across individual components in series add up to equal the pd across all of them.
