Electricity Flashcards
What color is the live wire
Brown
What color is the neutral wire
Blue
What color is the Earth wire
Green and yellow stripes
What’s the use of the neutral wire
The neutral wire complete the circuit
What’s the use of the live wire
The live wire carries the alternating potential difference from the supply
The live wire is a safety wire to stop the appliances becoming live
What is the potential difference between the live wire and the Earth wire
230 V
Where is the neutral wire
The neutral wire is close to the Earth
What is the use of the Earth wire
The Earth where is a safety wire to stop the appliances become in live
The Earth where is at 0V It only carries a current if there is a fault
Means electricity is an AC supply in the United Kingdom has a frequency of what
It has a frequency of 50 Hz and is about 230 V
The every day electric Apliances are designed to do what
To bring about energy transfers
The amount of energy and appliance transfers depends on what
How long the appliance is switched on for and the power of the appliance
How is work done
Work is done when charge flows in a circuit
What is the national grid
The national grid is a system of cables and transforms linking power stations to consumers
How is that electric power transferred
The electric power is transferred from power stations to consumers using the national grid
What are step up transformers used for
Step up transformers are used to increase the potential difference from the power station to the transmission cables
What’s the use of step down transformers
Step down transformers are used to decrease to a much lower value the potential difference of the domestic use
What is the electric current a flow of
The electric current is a flow of electrical charge
What does the current through a component depend on
The resistance (I) of the component and the potential difference (V) across the component
The greater the resistance of the component What happens to the current
The greater the resistance of the component the smaller the current for a given potential difference (pd) across the component
What happens to the resistance of a thermistor when the temperature increases
The resistance of a thermistor decreases as the temperature increases
What happens to the resistance of an LDR when the light intensity increases
The resistance of an LDR decreases as the light intensity increases
What is the use of an LDR
It switches lights on when it gets dark 
What’s the difference between direct current and alternating current
Direct current (DC): the electric charge (current) only flows in one direction
Alternating current (AC): the electrical charge (current) changes directions
Describe the difference between series and parallel circuit
A series circuit is where resistors are connected together in the same line, however in a parallel circuit resistors are connected in parallel.
Explain why adding resistors in a series increases the total resistance while adding resistors in parallel decreases the total resistance?
In a parallel circuits the net resistance decreases as more components are at it because there are more paths for the current to pass through. Adding resistors in series always increases the total resistance the current has to pass through each resistor intern so adding an additional resistor adds to the resistance already encountered.
Explain the design and use of DC circuits for measurements and testing purposes.
A DC circuit is a direct current that is steady constantly flowing in the same direction in a circuit from positive to negative.
Define potential difference
Potential difference is Voltage
Describe a parallel circuit
The potential difference across each component is the same or in other words the voltage across each component is the same. The total current of the whole circuit is the sum of the currents through the separate components.
What does linear and nonlinear mean
A linear circuits is one who’s parameters are constant with time and they do not change with voltage or current, a nonlinear circuit is that circuit who’s parameters change with voltage or current.
What is a series circuit
In a series circuit the same current flows through each component. The total potential difference of the power supply is shared between the components. The total resistance of each component is the sum of all the components.
For an electric charge to flow through a closed circuit what must it include
It must include a source of potential difference
How do you increase efficiency of intended energy transfer
Thermal insulation lubrication and streamlining
Describe the main energy source available
The main energy sources available are fossil fuels such as coal gas and oil nuclear power biofuel wind power hydroelectricity tidal power and solar power and geothermal power and sun and water and sun and water waves.
Why are some energy sources more reliable than others
The non-renewable sources are the most reliable as they can be used at any time. However they produce more greenhouse gases.
Name some energy sources that are renewable and nonrenewable
Sunlight and wind renewable resources
fossil fuels such as coal oil and gas are non-renewable
How can you reduce unwanted energy transfers
Thermal insulation lubrication and streamlining
Where is energy transferred in a closed system
In a closed system there is no energy added and no energy can escape the total energy in the system remains the same
