electric current. electric current electric current is the rate of electron flow past a specific...
TRANSCRIPT
Electric currentElectric current is the rate of electron flow past a specific point in the circuit (how fast electrons pass through a point in the wire).
The symbol for electric current is I.
The units of electric current is amperes or amps (A).
Electric current can be compared to water current:
Comparison Water Current Electric Current
Conductor
What is flowing
Units for flowing particles
Time interval
Rate of flow (current)
pipe or hose wire
water molecules electrons
Litres (L) of waterCoulombs (C) of charge(1 C = amount of charge on 6.25x1018 electrons)per second (s) per second (s)
litres per second coulombs per second 1 ampere (A) = 1C/s
AMMETERS are used to measure the
________________ in a circuit.electric current
How to use an AMMETER
How to use an AMMETER
I0I0 the current coming from
the power source.
I1 the current passing through the bulb.
Example: We want to measure the current at I0 and I1 for the circuit below.
I1
To measure the current at I0 or I1, the circuit must
be _________________ to make the ammeter
part of the circuit. The ammeter is then
connected in _____________.
disconnected
How to use an AMMETER
series
Connect the terminal of
the ammeter to the wire(s) leading to the
___________________terminal of the power
source.
positive / red
How to use an AMMETER
positive / red
Connect the terminal of
the ammeter to the wire(s) leading to the
___________________terminal of the power
source.
negative / black
How to use an AMMETER
negative / black
How to Read an AMMETER
What is the reading on this ammeter?
If you connected the circuit to the 3A setting on the ammeter, then the current reading is 1.5 A.
If you connected the circuit to the 1A setting on the ammeter, then the current reading is 0.5 A.
How to Read an AMMETER
What is the reading on this ammeter?
If you connected the circuit to the 3A setting on the ammeter, then the current reading is 2.15 A.
If you connected the circuit to the 1A setting on the ammeter, then the current reading is 0.72 A.
How to Read an AMMETER
What is the reading on this ammeter?
If you connected the circuit to the 300 mA setting on the ammeter, then the current reading is 215 mA.