Electricity Flashcards
What is energy?
Energy is the ability to do work.
What is the formula for ‘Work done’?
Force x Distance.
What is electricity?
A type of energy that can build up in one place or flow to another.
When energy is gathered in one place, what is it called?
Static electricity.
When energy moves from one place to another, what is it called?
Current electricity.
What do we call an object that gains electrons?
Negatively charged.
What do we call an object that loses electrons?
Positively charged.
What do like charges do?
They repel.
What do unlike charges do?
They attract.
How are objects charged?
- By Friction. 2. When only electrons are able to travel.
What is a danger of static electricity?
There are inflammable gases or vapours, or a high concentration of oxygen.
What are some uses of static electricity?
- Insecticide sprays. 2. Paint spraying. 3. Defibrillators.
What is electric current?
The flow of electrons.
If electricity is to flow, what must it have?
It must have a power source and a complete circuit.
In which direction do electrons flow?
From negative to positive.
What do we measure current in?
Amps (A).
What is an electrical circuit?
An electrical device that provides a path for electricity to flow.
What is a series circuit?
An electrical circuit with only one path, but several components.
What are the characteristics of a series circuit?
- If one component breaks, the circuit is broken. 2. If you put more lamps into a series circuit, the light in each lamp will become dimmer than before.
What is a parallel circuit?
An electrical circuit with two or more paths.
What are the characteristics of a parallel circuit?
- If a lamp ‘blows’, the components on different wires keep working. 2. The lamps stay the same brightness if you add more in parallel.
In which direction does current flow in conventional current?
From positive to negative.
The current is ____________ in a series circuit.
‘the same everywhere’.
Current on a parallel circuit is ______.
‘shared’.
In a parallel circuit, when measuring current through a component, the ammeter is always connected in _____ with that component.
‘series’.
What is voltage?
A measure of the difference in electrical energy between two parts of a circuit.
Voltage in a parallel circuit is _________.
‘equal everywhere’.
What is resistance? What is it measured in?
The opposition in an electrical component to the current flowing through it. It is measured in Ohms.
What is a resistor?
Something that electricity cannot travel through easily.
An electrical conductor has a ___ resistance.
‘low’.
An electrical insulator has a ____ resistance.
‘high’.
The resistance _______ when you add more components in series.
‘increases.
What are the three main types of resistor?
- Fixed resistors. 2. Variable resistors used in dimmer switches. 3. Special resistors such as thermistors and LDRs.
What is a diode?
A component that allows current to flow in one direction only.
What is an LED (light-emitting diode)?
A special kind of diode that glows when electricity passes through it.
What is an LDR (light-dependent resistor)?
These are used to detect light levels. Their resistance decreases as the light intensity increases.
