P4 Flashcards
What is current
A measure of the flow of electrons around the circuit
What is potential difference
The force driving the flow of electrons provided by the cell or battery
What is resistance
Everything that resists or opposes the flow of electrons
Which way does the current flow around a circuit
From positive to negative terminal
What happens as you increase the voltage given the resistance is a constant
The current should increase proportionally to the potential difference
Draw the current-pd graph for a filament lamp and diode
…
What is charge
A measure of the total current that flowed within a period of time
How do we measure the current of a circuit
Using an ammeter connected in a series of
How can we measure the potential difference of a component
Using a voltmeter connected in parallel
What happens when you rub two electrically insulating materials together
The electrons are rubbed of one material and deposited on the other.
What is static electricity
When rubbing two insulating materials together, the material that gains electrons become negative. The one that has lost electrons becomes postitive. So there is an attraction.
What does a charged object create
An electrical field around itself
What happens when a second charged object enters another charged objects electric field
It experiences a force
What is a diode
A component that allows current to flow in only one direction
What is a light emitting diode (LED)
emits light as a signal of when current passes through it
What does ohms law only apply to
A resistor at a constant temperature
look at current-potential difference graph for a resistor
page 27
what is an ohmic conductor
a component that behaves according to ohms law
why does the resistance of a filament lamp increase as the current increases
the resistance of the filament lamp increases as temperature increases
what happens if you reverse the current in a diode
it has very high resistance so is virtually zero as diodes only allow current to flow in one direction
what does current want to do in a parallel circuit
flow through the route with least resistance
