Name
Unit 15: Electrical Circuits & Their Applications
Section 1 – Electrical Symbols and definitions:
Cell
Battery
Switch
Filament Lamp
Fixed Resistor
Thermistor
Light Emitting Diode (LED)
Light Dependent Resistor
(LDR)
Rheostat
Capacitor
Voltmeter
Ammeter
, Name
Glossary of Terms:
Current (Ampere): One Ampere is defined as the current that flows with electric charge of one Coulomb per second.
Potential Difference (volt): Potential difference is the difference in the amount of energy that charge carriers have
between two points in a circuit
Electrical Charge (coulomb): The coulomb is defined as the quantity of charge that passes through the cross section
of an electrical conductor carrying one ampere for one second.
Resistance (ohm): Resistance is a measure of the opposition to current flow in an electrical circuit. Resistance is
measured in ohms.
Conductance (siemen): Conductance is an expression of the ease with which electric current flows through a
substance
Electrical Power (watt): One watt is defined as the energy consumption rate of one joule per second.
Capacitance (farad & sub-units): Capacitance is the ratio of the change in an electric charge in a system to the
corresponding change in its electric potential.
Current in terms of rate of flow mobile charge carriers: There are many, many charge carriers moving at once
throughout the whole length of the circuit. Current is the rate at which charge crosses a point on a circuit. A
high current is the result of several coulombs of charge crossing over a cross section of a wire on a circuit.
Electromotive force (EMF) as a measure of ratio of energy supplied per unit charge: The electromotive force (e)
or e.m.f. is the energy provided by a cell or battery per coulomb of charge passing through it, it is measured in volts
(V). It is equal to the potential difference across the terminals of the cell when no current is flowing.
Conductance & Resistance in relation to density of mobile charge carriers: The electrical resistance of an object is a
measure of its opposition to the flow of electric current.
Section 2 – Electrical Formulae and relationships:
The first formulae are Energy supplied and you
would use that formulae by doing W=V/T which
'power' is the rate of working and is equal to the
work done divided by the time taken.
The second is Kirchhoff's current law (1st Law)
states that current flowing into a node (or a
junction) must be equal to current flowing out of
it. This is a consequence of charge
conservation. Kirchhoff's voltage law (2nd Law)
states that the sum of all voltages around any
closed loop in a circuit must equal zero.
The third formulae are Ohm’s law, a law stating that electric current is proportional to voltage and inversely
proportional to resistance. The formulae for this is V=IR
The fourth formulae are power is the rate of doing work or of transferring heat, i.e. the amount of energy
transferred or converted per unit time. Having no direction, it is a scalar quantity. The formulae for this is P=IV, P=I 2R.
The fifth formulae is charge, charge also known as electric charge, electrical charge, or electrostatic charge and
symbolized q, is a characteristic of a unit of matter that expresses the extent to which it has more or fewer electrons
than protons. The formulae for this is Q=IT
Unit 15: Electrical Circuits & Their Applications
Section 1 – Electrical Symbols and definitions:
Cell
Battery
Switch
Filament Lamp
Fixed Resistor
Thermistor
Light Emitting Diode (LED)
Light Dependent Resistor
(LDR)
Rheostat
Capacitor
Voltmeter
Ammeter
, Name
Glossary of Terms:
Current (Ampere): One Ampere is defined as the current that flows with electric charge of one Coulomb per second.
Potential Difference (volt): Potential difference is the difference in the amount of energy that charge carriers have
between two points in a circuit
Electrical Charge (coulomb): The coulomb is defined as the quantity of charge that passes through the cross section
of an electrical conductor carrying one ampere for one second.
Resistance (ohm): Resistance is a measure of the opposition to current flow in an electrical circuit. Resistance is
measured in ohms.
Conductance (siemen): Conductance is an expression of the ease with which electric current flows through a
substance
Electrical Power (watt): One watt is defined as the energy consumption rate of one joule per second.
Capacitance (farad & sub-units): Capacitance is the ratio of the change in an electric charge in a system to the
corresponding change in its electric potential.
Current in terms of rate of flow mobile charge carriers: There are many, many charge carriers moving at once
throughout the whole length of the circuit. Current is the rate at which charge crosses a point on a circuit. A
high current is the result of several coulombs of charge crossing over a cross section of a wire on a circuit.
Electromotive force (EMF) as a measure of ratio of energy supplied per unit charge: The electromotive force (e)
or e.m.f. is the energy provided by a cell or battery per coulomb of charge passing through it, it is measured in volts
(V). It is equal to the potential difference across the terminals of the cell when no current is flowing.
Conductance & Resistance in relation to density of mobile charge carriers: The electrical resistance of an object is a
measure of its opposition to the flow of electric current.
Section 2 – Electrical Formulae and relationships:
The first formulae are Energy supplied and you
would use that formulae by doing W=V/T which
'power' is the rate of working and is equal to the
work done divided by the time taken.
The second is Kirchhoff's current law (1st Law)
states that current flowing into a node (or a
junction) must be equal to current flowing out of
it. This is a consequence of charge
conservation. Kirchhoff's voltage law (2nd Law)
states that the sum of all voltages around any
closed loop in a circuit must equal zero.
The third formulae are Ohm’s law, a law stating that electric current is proportional to voltage and inversely
proportional to resistance. The formulae for this is V=IR
The fourth formulae are power is the rate of doing work or of transferring heat, i.e. the amount of energy
transferred or converted per unit time. Having no direction, it is a scalar quantity. The formulae for this is P=IV, P=I 2R.
The fifth formulae is charge, charge also known as electric charge, electrical charge, or electrostatic charge and
symbolized q, is a characteristic of a unit of matter that expresses the extent to which it has more or fewer electrons
than protons. The formulae for this is Q=IT
