Electricity New Flashcards
electrical current
the rate of flow of electric charge
what is current measured in
amperes/amps (A)
1 amp = 1 coulomb flowing in one second
which way does current flow
positive terminal to the negative terminal of a cell
how to measure current
ammeter
what is charge measured in
coulombs (C)
equation linking current, charge and time
Q = I x t
Q = charge
I = current
t = time
voltage
-the energy transferred per unit charge passing between two points
-measured in volts(V)
what is one volt equivalent to
1 joule per coloumb
what happens when electrons flow through a cell
gain energy
how much energy do electrons gain when do flow through a cell
depending on the voltage of the cell, e.g. 12V mean 12Joules per coulomb
how to measure voltage
using a voltmeter
how must a voltmeter be set up
in parallel with the component being measure
why must voltmeters be set up in parallel
they have a very high resistant so it does not alter the flow of current
equation linking energy transferred, charge and voltage
E = Q x V
resistance
-the opposition of a component to the flow of electric current through it
-measured in ohms (Ω)
