P10 | electricity & circuits Flashcards
what do cells do?
transfer electrical energy to the electrons in the circuit (voltage)
what do ammeters do?
measures current flowing through a circuit (must be placed in series to the component)
what do components do?
transfers electrical energy into other forms, causing electrical energy to drop and creating a potential difference
what do voltmeters do?
measures the voltage of a cell/the potential difference of a component
must be placed in parallel to the component/cell
what do variable resistors do?
changes the flow of current in a circuit by changing the resistance
in which circuit is the current the same everywhere?
series circuit
in which circuit is current shared equally between branches provided the resistance is the same?
parallel circuit
in which circuit is voltage shared equally between components provided the resistance is the same?
series circuit
in which circuit is voltage the same on each branch?
parallel circuit
ways to increase current in a circuit:
- increase the voltage by adding another cell
- decrease the resistance by removing variable resistor
what is current?
the rate of the flow of charge (amps = coulombs per second)
coulombs / seconds
which particles carry charge?
electrons
what is potential difference?
the energy transferred per unit charge
voltage = energy (Joules) / charge (Coulombs)
voltage = joules per coulomb
what is ohm’s law?
the voltage across a conductor is directly proportional to the current flowing through it (provided all physical conditions such as temperature remain constant)
resistance = voltage / current
what is resistance?
the opposition to the flow of charge
