Electricity Flashcards
What charges are in electricity
Positive and negative charges
What do like and unlike charges do
Like charges repel and unlike charges attract
describe an experiment to show the production and detection of electrostatic charges.
Rub a cloth on polythene rod. This takes away the negatively charged electrons. Then put it next to another rod. They should now attract as the electrons will attract to the positively charged rod.
what does it take to charge a body
The addition or removal of electrons
what is a conductor
A material that allows charge to flow through it
What is an insulator
A material that doesn’t allow charge to flow through it.
What is charge measured in
Coulombs (C)
What is the direction of an electric field
Away from positive and towards negative
What is an electric field
A region in which an electric charge experiences a force
What is current
The flow of charge
What is current in metals
The flow of electrons
What is current
The rate of flow of charge
What is the equation relating current and charge
I (current ) = Q (charge) / t (time)
What is the direction of flow of electrons and what is the flow direction of conventional current
Electrons flow from negative to positive and conventional current goes from positive to negative.
What is emf measured in
Volts
What is potential difference measured in
Volts
What is 1 volt equivalent to
1 joule / coulomb
What is the equation for resistance
R = V / I
What is the equation for resistance
R = V / I
Describe an experiment to determine resistance
Set up a circuit with an ammeter put in series at any part to determine the current and a volt meter put in parallel to the component you want ypto measure the resistance from. Take down the readings. Then put your numbers into the equation R=V/I
What is the equation for power
P=IV
what is the equation for energy
E=IVt. think of ItV news.
How do you calculate the combined resistance of two resistors in series
You add them up
What is different with the current in a parallel circuit
The current from the source is larger than the current from each branch.
What is different about the combined resistance of two resistors in parallel
The combined resistance of both in parallel is less than of one by itself
How do you calculate the resistance of two resistors in parallel
1/Rt=1/R1 + 1/R2
