Electricity Flashcards
What are electrical currents measured in?
amps (ampere)
What happens when you add more components?
Resistance increases
What happens to the current when the resistance increases?
It decreases/gets weaker
Current in a parallel circuit
A1=A2+A3
Current in a series circuit
current is equal all the way around
How many wires are there in a plug and what are they?
3
Live wire: brown
Neutral wire: blue
Earth wire: green and yellow
Where is the Earth wire connected?
from the plug to the casing
Where is the fuse?
On the live wire
What happens when you are electrocuted?
Your muscles contract
Are nerves good conductors of electricity?
Yes
What is a fuse?
A thin wire that is designed to melt if the current gets too hot
How can the fuse be adapted to withstand more current?
the thicker the wire, the more current it can withstand before it melts
What does the earth wire do if the casing becomes live?
If the casing becomes live, the earth wire would redirect the electrical current down to the plug which would be the easiest/quickest route as it would take longer/be more difficult for the current to pass through a human.
What direction does electricity flow?
From the plus to the minus side of the cell
What is current?
Current is the flow of charge around a circuit. The moving charges are negative electrons. Current can only flow if the circuit is complete with no gaps.
What happens to the current in a circuit?
The current isn’t used up as it flows through a circuit. The total current is always the same
What happens if we use more batteries?
The current will be greater so the bulbs will be brighter.
What happens if we use more bulbs?
The current will be weaker so the bulbs will be dimmer because the bulbs cause resistance due to their thin wire filament
How big are charges and where are they? What do the charges carry? How fast do the charges move, relatively? What is the electric current?` Where do the charges deliver energy? What does the battery do? Where to the charges collect the energy?
What happens if the charges speed up?
- Charges are atom sized particles already in the wire.
- The charges carry energy
- All the charges move at the same speed
- The electric current is the number of charges passing a point at each second.
- The charges deliver energy to the bulb where it is transferred into heat and light
- The battery provides energy and makes the charges move.
- Charges collect energy at the battery
- Charges return to the battery to collect energy
- If the charges speed up, more energy is delivered to the bulb in a certain time
- If more energy is carried by each charge, more energy is delivered to the bulb in a certain time.
What happens if a battery is the wrong way around?
If a battery is the wrong way around, it cancels out.
Ammeter
A device used to measure electric current
Ampere
Unit of current
e.g.
“The current in the bul is 4 amps or amperes (A)”
Battery
A chemical supply of energy
Common battery voltage include 1.5 V and 9 V
Cell
A store of internal energy that can be transferred as an electric current in a circuit
Circuit
A closed loop through which current moves: from a power source, through a series of components, and back to the power source
Circuit diagram
A diagram that represents an electric circuit using lines and symbols
Circuit symbol
Symbol used to represent an electrical component in a circuit diagram
Conductor
A material which allows charge to move easily through it
Electric charge
The electrical state of an object, which can be positively or negatively charged.
Electric current
The movement of electrically charged particles, for example, electron moving through wire or ions moving through a solution
Electron
Subatomic particle, with a negative charge and a negligible mass relative to protons and neutrons
In parallel
In a parallel circuit, the current divides into 2 or more paths before recombining to complete the circuit.
Lamps and other components in these different paths are said to be in parallel. The paths are called branches.
In series
Connected to a circuit in such a way way that the same current flows through each component in turn. Opposite of parallel
Insulator
Material that does not allow charge or heat to pass through it easily
Ohms
The unit of electrical resistance, whose symbol is Ω
