2.3 Currents in Electrical Ciruits Flashcards
What is the current in an electrical circuit?
The flow of electric charge round a circuit
What is the potential difference/voltage?
The work done per coulomb of charge that passes between 2 points in a circuit
What are the characteristics of components connected in series?
- The total resistance is the sum of the resistance of all the components in the circuit
- The current is the same everywhere in the circuit
- The total potential difference is shared between the components
What are the characteristics of components connected in parallel?
- The potential difference across each component is the same
- The total current through the whole circuit is the sum of the currents through the separate components
What does an LED do and what does it stand for?
Light Emitting Diode - emits light when a current flows through it in the forward direction
What does an LDR do and what does it stand for?
Light Dependant Resistor - The resistance decreases as light intensity increases
What does a thermistor do?
It’s a temperature dependant resistor, the resistance decreases as the temperature increases
How is static electricity made?
Insulating materials are rubbed against each other. Electrons move from one material to the other. One material is positively charged and the other is negatively charged
What happens to objects that carry the same charge?
They repel
What happens to objects that have different charges?
They attract
What is the unit for current?
A (Amps)
What is the unit for voltage?
V (Volts)
What is the unit for resistance?
Ohms
What does the current-voltage graph look like for a resistor?
What does the current-voltage graph look like for a filament lamp?