Electricity and Circuits Flashcards
What is an electric current?
The flow of electrical charge around a circuit
Which way do electrons flow in a circuit?
From - to +
Which way does conventional current flow in a circuit?
From + to -
In series circuit what does potential difference around the circuit have to add up to?
The cell voltage
What does the current in the different branches of a parallel circuit have to add up to?
The current leaving the cell
How is the current split in a series circuit?
It’s the same all around
In a parallel circuit how is the voltage split?
It’s the same all around
How do you calculate charge?
Charge (C) = current (A) x time (s)
What do you measure current with?
An ammeter
What do you measure potential difference with?
A voltmeter
How do you calculate the amount of energy transferred?
Energy transferred (J) = charge moved (C) x potential difference (V)
What is Ohm’s law?
Potential difference = current x resistance
How can the resistance of a circuit be changed?
Using fixed or variable resistors
What happens to the current as the resistance increases?
The current decreases, as the resistance decreases, the current increases
If there are two resistors in a series circuit, one with of a resistance of 2Ω and the other with a resistance of 4Ω what is the total resistance of the circuit?
6Ω