Eletricity Flashcards
Series
Circuit where current flows through all components in one
Parallel
Circuit where current flows through components in 2 or more pathways
Current
The rate of flow of electrical charge, measured in Amperes(A)
Voltage
Also known as potential difference, the electrical potential energy per unit charge
Resistance
The measure of how much a material reduces the flow of electricity, measured in Ohms(Ω)
Electrical conductor
A substance that allows charge to flow easily due to low electrical resistance
Electrical resistance
A substance that does not allow current to flow easily due to high electrical resistance
Power
The energy transformed per second by a component in a circuit, measured in Newtons(N)
Fuse
A thin piece of wire that will melt if current increases above a certain level, it is a safety component
Circuit breaker
A switch the stops the flow of current in a suddenly overloaded circuit, a resuable safety component
Force
A push or pull on an object that can cause a change in speed, shape or direction
Resultant/net force
The overall force acting on ann object
Friction
The force that always acts opppisite to motion or attempted motion
Average speed
The rate of change of distance or how fast you change your distance travelled, measured in meters per second(m/s)
Acceleration
The rate of change in speed, measured in meters per second per second(ms-2)
Weight
The downward force caused by gravity on an object, measured in newtons(N)
Mass
The amount of matter that makes up and object, measured in kilograms(kg)
How does an ammeter measure current
The two leads of the ammeter in the circuit must be connected so that the current flows through the ammeter. The Ammeter must be connected series with the electrical circuit, as it is ‘counting’ the electrons as they move past the point they are connected to.
Advantages of series circuit
The current is the same everywhere, meaning the brightness of the bulbs is equal and controlled. And all components can be controlled with one switch/fuse/circuit breaker.
Advantages of parallel circuit
A faulty component in a cricuit would cause a branch to stop working instead of the whole circuit
Multiple pathways for current flow back to power source
Describe how voltage supplied in a circuit affects the current flowing in the circuit
As voltage increases, the push on the electrons also increases as voltage is the potential energy per charge (electron). This results in the relationship between Voltage and Current, so that if voltage is increased it will result in an increase in current. (voltage pushes the free electrons around the circuit creating a current - it can be thought of as pressure in a water pipe). If you increase the voltage and the resistance stays the same, the current will increase. V = IR
State - As voltage increases, the push on the electrons also increases
Define voltage and current
State - Voltage pushes the free electrons around the circuit
If voltage increase resistance stays the same - current will increase
V = IR
Explain how conductors conduct electricity
Conductors have free elctrons to move and can so allow charge to flow as there is low electrical resistance. The electrical charge that flows in metals will be electrons.
Describe the relationship between current and resistance in a circuit
Resistance is the measure of how much a material can reduce the flow of electricity measured in ohms(omega sign) while current is the rate of flow of electrical energy, measured in amperes(A).
The more resistance in a circuit, the harder it is for current to flow. This means the flow of current will decrease. If resistance in a circuit increases, the current will decrease (this makes sense as current describes the number of electrons passing a point per second – if the resistance or “difficulty for electrons to flow” increases, the number of electrons passing a point will be less every second). Similarly, if resistance in a circuit decreases, the current will increase. This is an inverse relationship, that as one increases the other decreases.
Define both resistance and current
- State - More resistance in a circuit harder for current to flow
- State - If resistance in a circuit increases, the current will decrease
Current describes number of electrons passing a point every second - if resistance increases, harder for electrons to flow current will be less
If resistance decreases current increases.
Switches
When its closed it completes a circuit and allows electrons to keep floating through the wire
Fuses
A fuse is a thin piece of wire that will melt when the current increases above a certain level. It is a safety component in a circuit.
Circuit breakers
A circuit breaker is an automatic switch that stops the flow of current in a suddenly overloaded electrical circuit.
compare power usage
Fan 2 provides a higher power output. This means that it is able to transform more electrical energy into kinetic energy per second than fan 1. This means that fan 2 is a better choice for cooling down Fiona.
