P4.2 - current/charge/volatge/resistance Flashcards
electric current
-flow of charge
-more electron flow per sec = bigger current
size of current =
rate of flow of charge
or charge per sec
electric charge unit
coulombs C
Current unit
amperes A
1 amp = how many c
1C per sec
equation for charge flow, current, time
charge = current x time
conventional flow
-positive to negative
electron flow
-negative to positive
Components of a circuit: cell
-pushes electrons around circuit
Components of a circuit: battery
2 or more cells
Components of a circuit: switch
-enables current to turned on/off
Components of a circuit: lamp
-emits light when current passes through
Components of a circuit: diode
allows current through one direction only
Components of a circuit: LED (light-emitting diode)
emits light when current passes the right way
Components of a circuit: ammeter
measures current
Components of a circuit: fixed resistor
limits current in a circuit
Components of a circuit: variable resistor
allows current to be varied
Components of a circuit: fuse
melts and breaks circuit if current it too big
-safety mechanism