Topic 8 Energy Transfer In Electrons Flashcards
What is the difference between a cell and a battery?
A cell is only one source of chemical energy, a battery is two or more sources of chemical energy together
How can energy be transferred?
In electrical systems by the movement of electric charges
How does the chemical energy in cells get transformed into electrical energy?
Putting cells in a circuit enables electrons in the conducting wires to move/flow through the wires, becoming electrical energy.
What is electrical energy?
It is the flow of energy through a circuit.
Which is the positive terminal of a battery?
It is the terminal with the nipple on it.
What is an open circuit?
It is a circuit where there is a break in the flow of energy.
What is the plastic covering for on conducting wires?
To keep the electrical current inside of the wires, so that you don’t get shocked.
Which conducting wires are positive and negative?
Red-positive
Black-negative
Why is it important to distinguish the different wires?
So that we can connect positive to positive and negative to negative
In what forms can chemical energy be found?
Battery/cell
Fuel
Food
Muscles
What kinds of energy are there?
Chemical Elastic Gravitational Nuclear Kinetic Radiant Thermal Sound
What are the components of a circuit?
Conducting wires
Switch
Cell/battery
Resistors
What are conducting wires?
A conductive metal covered in a plastic casing used to transfer electrons. Copper is the most common metal in wires that transport electricity over short distances.
Why are conducting wires covered in a plastic casing?
Protects us from shocks
Colour codes the cables for ease of use.
What is a switch used for?
It is to break the flow of electric charge in the conducting wires.
What does a mains switch do?
It controls how much electrical energy flows into the building.
Why does a bulb light up when connected to a cell?
Chemical reactions occur inside the cell, and potential energy is transferred to the kinetic energy of the electric charges.
Which terminals do the electrons leave and enter the battery or cell?
Positive terminal-flowing in
Negative terminal-flowing out
What are resistors?
They are materials that resist the flow of charge in a circuit. They are useful for varying amounts of energy. They also get hot very quickly
What does a light bulb contain?
A filament
What is a filament?
A resistance wire inside a light bulb. It is a wire that is coiled up that can produce heat and light.
How does a filament work?
It heats up, producing light and heat energy
What is an alloy?
A mixture of metals
What are resistors normally made out of?
Normally an alloy
What is a cell made out of?
Chemicals
What is a resistor designed to do?
To transform electrical energy into other forms of energy and to control the flow of energy to prevent a fire.
What is a coulomb?
A package of 6 240 000 000 000 000 000 electrons
How can a resistor dim a light bulb?
A resistor slows down the flow of electrons and uses the electricity for heat energy, which means less is used for light energy.
What is a short circuit?
Give an alternative pathway and the coulombs will flow straight back to the cell. This may cause a fire.
What causes a magnetic field?
An electric current
What is a filament usually made of?
Tungsten
What can an electric current do?
Create an electric magnetic field
What happens when two magnets get closer?
The force gets stronger
How do you measure a magnetic field?
With a compass
How do you create a magnetic field?
When a current moves through a straight wire
What is the magnitude of a force?
The strength of a force, i.e strong or weak
What is a current?
The flow of electrons moving through a conducting wire. It talks about how many coulombs of charge are passing a point per second, and how fast they are flowing.
What things produce a magnetic force?
A magnet
A current that is flowing through a straight wire
What is the direct relationship between the current and the magnetic field?
A strong current produces a strong magnetic force
A weak current produces a weak magnetic force
What is the inverse relationship between the radius of the magnetic field and the magnitude?
The smaller the radius, the stronger the force
The larger the radius, the weaker the force
i.e. The closer you are, the stronger the magnetic field is
How do you determine the direction of the magnetic field?
By the right hand rule
What is the right hand rule?
Make a fist with your right hand
Stick your thumb out
Curl your fingers
Make your fingers look like they are curling in the same direction as the flow of electrons
The way your thumb points is the direction of the current
What is the direct relationship between the coils of wire and the magnitude of a magnetic field?
The more coils of wire there are, the stronger the magnetic field
The fewer coils of wire there are, the weaker the magnetic field
What substances usually create ionic substances?
Elements on the opposite sides of the periodic table
How do you know which elements in an electrolysis reaction will be attracted to which electrode?
Elements on the left side of the periodic table is positive
Elements of the right side of the periodic table is negative
What is electricity?
Electrical charge
What is a circuit?
A path that is created for electricity to flow through
What is an electric current?
The flow of electrical charge in a circuit
What is a cell?
An energy source
How do you draw a circuit diagram?
Use circuit symbols
Use a ruler for the conducting wires
Always draw your diagram in pencil
Always make your diagram in a rectangular shape
Never draw symbols on the corners of your diagram
What is a short circuit?
When electricity takes the easiest route available, rather than the route created for it
Why are short circuits dangerous?
When there is a strong enough current, e conducting ire smelt an the heat can cause fires
How do you create an electromagnet?
By coiling copper wire around an iron core.
Attaching a battery and turning it on allows the current to flow
Moving current creates a magnetic field
What is an electromagnet?
A moving current that creates a magnetic field
What will make an electromagnet stronger?
More coils of wire around the nail
A stronger power source
What is an ionic solution?
A solution that has both positively charged and negatively charged atoms
What is an example of an ionic solution?
Copper chloride that undergoes a decomposition reaction
In the decomposition reaction of copper chloride, which will be positive and which will be negative?
Copper-positive
Chlorine-negative
Which electrode loses electrons during electrolysis?
The positive electrode-the anode
Which electrode will gain electrons during electrolysis?
The negative electrode-the cathode
During the decomposition of copper chloride, which atoms will got to which electrode?
Copper-cathode
Chlorine-anode
During the decomposition of water, which atoms will go to which electrode?
Hydrogen-cathode
Oxygen-anode
What is a fuse?
A piece of metal in a circuit that melts when it overheats
What does a fuse do?
If too much electricity flows in a circuit, the fuse will melt, stopping the flow of electricity form causing a fire
What is the most common type of fuse?
A filament that is enclosed in a glass or ceramic and metal casing
What happens when you wrap the wire in an electromagnet in different directions?
The current will flow in two different directions. This causes the magnetic fields to cancel each other out. The magnet will therefore be weaker