Module 1.2 - Charge/Voltage/Resistance Flashcards
Define current?
rate of moving electrons measured in amperes ( A )
What is electric current?
the amount of charge which flows through a circuit every second. as current increases more electrons move through the circuit every second
How can you relate electric current to a water pipe?
the bigger the pipe the faster the water flows thorough. the bigger the conductor the faster the current flows through the circuit
Explain how electron flow works and how its different to conventional current
Electrons build up at the negative terminal of a battery because chemical are pushing them down (in a battery there is more positive than negative)
in an electron flow the electrons have been built up and once let go are immediately attracted the the positive terminal pulling them around the circuit.
What is the difference between an alternating current (AC) and a direct current (DC)
DC flows in one directions and is produced by solar cells and batteries whereas AC flows in both directions.Voltage in an AC is very inconsistent but in a DC it remains the same.
What is voltage?
voltage ( V ) is produced when we give charge (electrons) potential energy in a battery/energy source. The more potential energy is given the more voltage they have. As current flows through a circuit all potential energy (voltage) is lost
What is Resistance?
Resistance ( R ) slows the flow of current.
The harder the resistance the harder to push charge through a circuit and the more heat and light is produced.
What does the resistance of a material rely on?
- L - length of conductor (m)
- A - cross sectional area of conductor (m2)
- p - resistivity of material (ohms/m)
How do you calculate the resistance of material based on these three things?
R = resistivity x length
————————–
area
What is Ohms law?
Voltage = Resistance x Current Resistance = voltage divided by current Current = voltage divided by resistance
