P2 - Electricity Flashcards
What is voltage
The force from the power source that pushes the electrons through the circuit
What is the voltage measured in
Volts (V)
What is current
The movement of charge through a circuit
What is the current measured in
Amps (A)
What is the formula for resistance
Resistance = Voltage/Current
What are the factors that affect resistance (there are 4 of them)
Material of wire, length of wire, thickness of wire, temperature of wire
How do you work out the resistance in a series circuit
It is the total sum of all the resistors. R1+R2=RT
How do you work out resistance in a parallel circuit
1/RT=1/R1+1/R2
What does a thermistor do
A thermistor varies the resistance based on the temperature of the surroundings
Thermistor 1 is 20oC and Thermistor 2 is 40oC. Which has the higher resistance?
Thermistor 1 has a higher resistance because thermistors have a higher resistance when it is colder
What is the equation that links current, charge and time
Charge = Current x Time/C = A x S
What is an ohmic conductor
An ohmic conductor is when the current increases directly to the proportion
What happens to the resistance of a thermistor as the temperature increases
The resistance decreases as the temperature increases
How is the potential difference vary between the components in a series circuit
The potential difference is shared between the components in a series circuit
How does the potential difference vary between the components in a parallel circuit
The potential difference is equal between each branch
