physics lesson 4 Flashcards
(27 cards)
Electric Circuits:
circuit is a path that allows electric current to flow.
Series circuit
One path for current; if one part fails, all stop.
Parallel circuit
Multiple paths; if one part fails, the rest still work.
wire
Path for electrons (current flows through).
battery
Power source (provides voltage, V
Resistor
Slows current (provides resistance, R).
Current (I)
Amount of charge moving (measured in Amps, A).
Voltmeter
Measures voltage (connected in parallel).
Ammeter
Measures current (connected in series)
Ohmmeter:
Measures resistance (circuit must be off)
Ohm’s Law:
V = IR
If you increase voltage or decrease resistance, current increases.
DC
From batteries, flows one direction.
AC
From wall outlets, changes direction.
current behave in a series circuit?
same everywhere in the circuit.
current behave in a parallel circuit?
splits among branches.
How is voltage distributed in a series circuit?
It is divided across each part.
How is voltage distributed in a parallel circuit?
same across all branches.
What happens to resistance in a series circuit?
All resistances add up.
What happens to resistance in a parallel circuit?
Total resistance decreases (it’s less than the smallest resistor).
What happens if one part fails in a series circuit?
The whole circuit stops working.
What happens if one part fails in a parallel circuit?
The rest keep working.
Longer wire
more resistance
Thicker wire
less resistance
fuse
Melts when overheated to stop current
