Electricity Flashcards
What is current?
The rate of flow of charge
Where does an ammeter go and why?
In series due to having a negligible resistance
What is the formula for current?
I = Q/t
What is potential difference?
The energy transferred per coulomb of charge
Where does a voltmeter go and why?
Parallel due to having a very high resistance
What is the equation for working out voltage?
V=W/Q
What is Kirchoff’s law for current in series?
That it is the same throughout
What is Kirchoff’s law for current in a parallel circuit?
The current into the junction = the current out if the junction
What is Kirchoff’s law for potential difference in series?
The sum of the P.d = The total E.M.F
What is Kirchoff’s law for potential difference in a parallel circuit?
The P.d is the same across each branch
What is Kirchoff’s law for resistance in a series circuit?
R1 + R2 = Rtotal
What is Kirchoff’s law for resistance in a parallel circuit?
1/R1 + 1/R2 = 1/Rtotal
What is resistivity?
The resistance of a 1m^2, 1m long sample of material
What is resistivity in relation to the material?
It is a property
What is the equation for resistivity?
R=PL/A