Electricity Flashcards
Define alternating potential difference
A continually oscillating current flow, which results in the potential difference across two points continually oscillating between a positive and negative value.
What are amps
A unit of current
What is attraction
A force pulling two opposite charges together, when they are brought
near each other
What is a coulomb
The unit of charge
What is a diode
A component that only allows current to flow through in the forward direction. They have very large resistances in the reverse direction.
What is direct potential difference
One-directional current flow
What is the earth wire
The green and yellow safety wire that prevents an appliance from becoming live . E.G. A kettle
What are electrical field lines
Lines representing an electric field, that point in the direction in which a positive charge would experience an electric force.
What is an electrical field
A region in which a charge will experience a non-contact, electric force. All charged objects have an electric field around them, and this field is stronger the closer you are to the charge.
What is electrical current
The rate of flow of electrical charge. Its value is the same at any position in a single closed loop.
Define electrical work
When charge flows in a circuit, electrical work is said to be done
What is a filament lamp
A light emitting component consisting of an enclosed metal
filament. Its resistance increases as the filament’s temperature increases.
What is insulation
The coating around power cables that prevent electrocution, they’re colour coded to allow for easy identification
What is a light dependent resistor
A resistor that is light sensitive and it’s resistance increases as temperature increases
What is a live wire
The brown wire that the alternating current runs through from the mains power supply
What is the neutral wire
The blue coloured wire that completes the circuit in the mains power supply
What is a non-contact force
A force experienced between two separate objects. Like gravity, electrical and magnetic forces
What is an ohmic conductor
A conductors who’s current flow is directly proportional to the potential difference across it, when held at a constant temperature
Ohms
The unit for resistance
What does parallel mean
Components connected in parallel have the same potential difference across each component. The total current is the sum of all the currents running through each component
What’s is repulsion
When two like charges are brought together. Eg the north of two magnets
What is the resistance
A measure of the opposite to current flow
What is a volt
The unit of potential difference
What is a thermistor
A component dependant on temperature, the resistance increases as temperature decreases
What is the national grid
The network of power stations, transformers and cables that connect consumers to power stations
What is a step up transformer
Devices that increase the potential difference generated from power stations. So that the electrical power transmitted along the transmission cables is at a higher potential
What is a step down transformer
Devices found between transmission cables and consumers that lower the potential difference of the power so it’s at safe usable levels
What is static charge
The charge caused by an imbalance of negative and positive charges in, or on, an objects surface. It’s often caused by electrons being rubbed from one surface to another
What is series
Components connected in series have the same current passing through each component but share the total potential difference of the power supply
Resistors in series
The total resistance is the sum of the resistances of the individual components
