Chapter P4 and P5- Electric circuits and Energy Appliances Flashcards
What’s a charged atom called?
What’s the charges of electrons, neutrons and protons?
How many number of protons and electrons does an uncharged atom have?
What happens if we add electrons to an atom?
What happens if we remove electrons from an atom?
An ion.
Electrons are negative (-1), protons are positive (+1) and neutrons are neutral (0).
An equal number of protons and electrons.
The atom becomes negatively charged because there are more electrons than protons.
The atom becomes positively charged due to there being more protons than electrons.
How can insulators be charged?
What is an example of an insulator being used?
What happens when the insulator is charged, concerning the electrons?
What does a charged object create around itself?
What happens if a charged object comes close to the first object?
What happens the closer the objects are together?
What do like charges do?
What do unlike charges do?
Through frictions when rubbed with another insulator.
A dry cloth.
The electrons will transfer from one insulator to another.
An electric field around itself.
It will experience a force.
The stronger the force is.
Like charges repel.
Unlike charges attract.
What does an LED stand for?
What is an electric current?
What is the size of the current?
What happens the larger the number of electrons that pass through a component each second?
What is the formula for calculating charge (in symbols)?
What is the formula for calculating charge?
What is charge measured in?
What’s current measured in?
What’s time measured in (for this equation)?
Light Emitting Diode.
A flow of charges.
The rate of flow of charge.
The bigger the current is passing through it.
Q= I x T
Charge= Current X Time Taken
Coulomb’s, C.
Amps, A.
Seconds, s.
What do diodes ensure?
What is potential difference?
What’s the formula for calculating potential difference across a component?
What’s this formula in symbols?
What’s potential difference and energy transferred measured in?
What does resistance tell us?
What’s the formula for calculating resistance (in symbols)?
What’s the formula for calculating resistance?
What’s resistance and potential difference measured in?
That current only flows in one direction through the circuit.
Potential difference tells us the amount of energy transferred by the charge.
Potential difference= energy transferred -:- charge
V= E -:- Q
Potential difference is measured in volts, V. Energy transferred is measured in Joules, J.
How difficult it is for the current to flow.
V= IR (here it’s R= V -:- I
Resistance= Potential difference -:- Current
Resistance is measured in ohms. Potential difference is measured in volts (V).
What will every component have?
What are the two formula’s for calculating current?
What are the two formula’s for calculating potential difference?
What’s the symbol formula for calculating resistance?
What is a wire said to be if it has the same thickness all the way along its length?
What three things does the resistance of this wire depend on?
What idea did scientists come up with to figure out how electricity occurred?
What do we now know about how electrons flow?
Some resistance.
V -:- R or Q -:- T.
R x I or E -:- Q.
V -:- I.
It is said to be uniform.
The length, material and thickness (cross-sectional area).
That something must flow from the positive terminal to the negative terminal in a circuit.
That electrons flow from the negative to the positive in a circuit.
What happens in a series circuit concerning the current on component?
What happens concerning the total potential difference of the power supply in a series circuit?
What happens to the total potential difference for cells connected in series?
What is equal to the total resistance of 2 or more components in series?
What is the symbol equation to show this?
What’s equal to the total current in a parallel circuit?
What’s the potential difference for parallel components in a parallel circuit?
The same current passes through each component.
The total potential difference of the power supply is shared between the components.
The total potential difference is the sum of the potential differences of each cell.
The sum of the resistance for each component.
R(total)= R(1) + R(2).
The total current is equal to the sum of the currents passing through a branch (basically add two branches and you get the total current ).
For the parallel components, the potential difference is the same.
What is the total resistance of two or more components in parallel less than?
What is static electricity?
What are the two types of current?
Describe both of them?
What type of current is the electricity supplied to homes?
What’s the electricity supplied to homes supplied at and at what frequency does it change direction?
The resistance of the resistor with the least resistance (basically the total resistance is less than the lowest resistor).
A build up of charge in one place.
Alternating and direct.
Alternating current= the current repeatedly changes direction. It flows one way and then another.
Direct current= The current only flows in one direction, which is what we get from a cell.
An alternating current.
230 volts and changes direction 50 times a second (frequency= 50 Hz).
Describe the features and purpose of earth wires?
What is a fuse?
What is a fuse made from?
What happens to the fuse when this melts?
What are the three types of wires in a cable plug?
What’s the current through a resistor at a constant temperature proportional to?
What does this mean?
What are these known as?
- Earth wires are cables in devices with metal on the outside that protect the user.
- They are connected to the ground so that if the device gets highly charged, it will go to the Earth and not through a person.
A device used to protect the device from very high currents should something go wrong.
It is made of thin wire that will melt if the electric current flowing through it gets too high.
It breaks the circuit which means the electricity can’t flow anymore.
Neutral, Earth and live.
The potential difference.
This means that the resistance doesn’t vary with current.
Ohmic conductors.
What are non-ohmic conductors?
What happens to the resistance of a filament lamp as the temperature of the filament increases?
What direction does the current through a diode flow?
How much resistance does the diode have in the other direction?
What is a filament?
What does LDR stand for?
What is power?
What is the formula for calculating the power in an electrical component?
What are the two formulas for calculating power in an electrical component (in symbols)?
The resistance of some components that change depending on the current flowing through them.
It increases.
In one direction.
A very high resistance.
A piece of metal in something, that heats up.
Light dependant resistor.
A measure of the amount of energy transferred (or work done) each second by a device.
Power (W)= Potential difference (V) x Current (A).
P= I x V or P= I squared x R - depending on whether you know what V is.
What happens when charge flows through a resistor?
What does this mean?
What are the two formulas to calculate the amount of energy transferred?
What two things determine the amount of energy transferred by a device?
What are electrical devices designed to do?
What are the two formulas for calculating efficiency?
Energy is transferred to the resistor so the resistor becomes hotter.
Work is done to transfer charge in a circuit.
Energy= Power x Time. Energy= Charge x Potential difference.
How long it’s switched on for and the power of the device.
Change energy from electrical energy to another form (often heat or kinetic).
Efficiency= useful output energy -:- total energy input. Efficiency= useful power output -:- total power input.
