Electricity Flashcards
What does insulation in a circuit do
It protects against unwanted current flow
Double insulation
The whole inside of a circuit is contained in plastic meaning no current is able to touch the outer insulator
An earth wire
An earth wire provides a low resistance path to the ground therefore in an event of a fault, the current is sent to the ground
Function of a fuse
A fuse breaks a circuit if too much current is flowing
Function of a circuit breaker
Interrupts the electrical current when it exceeds its design limitation
Mains electricity
The power brought into peoples homes
Explain use of series circuit
Series circuit is used in a fridge or freezer because it warns you if one part breaks. This is because all parts stop working
Explain the uses of a parallel circuit
Lights in a house because if one stops working all the others continue to work
Parallel circuit
One that has two or more paths for electricity to flow
Series circuit
One that only has one path for current to flow
Ohms law about current
Current is directly proportional to voltage and inversely proportional to resistance
What are used as a detector if a circuit is on
LED’s or lamps, buzzers as they turn on when current is present
Define current
The rate of flow of charge
Why is current conserved at a junction
Because charge is always conserved
In a series circuit: what is the total resistance?
What happens to voltage?
What happens to current?
Total resistance is the sum of all the components resistance
Voltage is shared between each component
Current is not used at and is the same throughout the circuit
Define voltage
The energy transferred per unit of charge
What is a conductor and give examples in
A conductor is a material that allows current to flow through them (e.g gold, aluminium (Metals))
What is an insulator and give examples
An insulator is a material that doesn’t allow charge through it (e.g glass, plastic)
What happens to like and unlike charges
Like charges repel and unlike charges attract
When does the electrostatic phenomena occur
When two bodies accumulate electrical charges, either by induction of friction
Dangers of electrostatic charges
Fuelling an aircraft there is a large build up of electrostatic charge that may make a spark to the earth. Because fuel is highly flammable it can easily ignite
Uses of electrostatic charge
Photo copying: parts of the page are negatively charged, the ink is positively charged so when sprayed onto the page it sticks at those points
