Subtopics
Electricity and Logic Gates
What is a series circuit?
In a simple series circuit, everything is connected in
one loop across the terminals of the battery.
there aren’t any points where the current can split
or join (these are called junctions).
This is a simple series circuit.
N.B
This circuit has two lamps connected in series.
Circuits are always drawn using straight lines.
ELECTRICITY
What is a parallel circuit?
A parallel circuit is one which contains a point (a junction) where
the current can split (point A) or join (point B).
This means that there is more than one path around the circuit.
Current in parallel circuit
The current splits up at the first junction and then joins together at the second junction.
If the bulbs are identical then the current will split evenly.
If the bulbs are not identical, then the current will not split evenly.
Energy transfer in circuits
Energy cannot be created or destroyed.
In all devices and machines, including electric circuits, energy is transferred from one type to another.
When this circuit is connected, chemical energy stored in the battery is transferred via electrical energy to heat and light energy in the bulbs.
The total amount of heat and light energy is the same as the amount of chemical energy lost from the battery.
LOGIC GATES
A logic gate is an
electronic component that
can be used to conduct electricity
based on a rule.
The output of
the gate is the result of applying
this rule to one or
more "inputs“.
TYPES
Nor Gates, Not Gate, Or Gate, Nand Gate, And Gate, Xor Gate, Xnor Gate.
Thermal Physics
heat
Heat is a type of energy.
Heat is the name for the type of kinetic energy possessed
by particles.
Heat energy is measured in joules (J).
How many joules are there in a kilojoule (kJ)?
temperature
The freezing point of water is defined as 0ºC (at 1 atm.).
The boiling point of water is defined as 100ºC (at 1 atm.).
Temperature is measured in degrees Celsius (ºC).
Temperature can be measured by a variety of different thermometers.
These include liquid in glass, digital,
thermocouple and bimetal strip thermometers.
Temperature is a measure of how hot or cold an object is.
Convection and density
To understand how heat can be transferred by convection,
the idea of density is important.
If water, oil and air are mixed
up,they will settle out in order
of density – which one will
rise to the top?
The air is least dense and rises
to the top,the water is the
most dense and sinks to the
bottom –it depends on how
far apart the particles are.
Conduction in metals
Metals are good conductors of heat because:
The free electrons can move around
and vibrate.
The heat energy is passed on by neighbouring
particles vibrating along the metal.
Metals have atoms inside them and lots of free electrons.
Moment of a Force
Moment equation
The moment of a force is given by the equation:
moment = force (N) x distance from pivot (cm or m)
Moments are measured in Newton centimetres (Ncm) or
Newton metres (Nm).
Calculating pressure
Pressure is the force per unit area
and is calculated using this formula:
pressure = force/area
Pressure is measured in:
Newtons per square metre (N/m2),
also called
pascals (Pa).
pressure can also be measured in
Pressure can also be measured in:
Newtons per square millimetre (N/mm2);
Newtons per square centimetre (N/cm2).
hydraulics
Hydraulic systems use the principle that pressure is
transmitted throughout a liquid.
They are used to transfer movement from one part of a
machine to another without linking the parts mechanically.
All hydraulic systems use two pistons linked via a pipe
carrying a special oil called hydraulic fluid.
Hooke’s law
