Electric Charges
What particle is responsible for creating an electric charge?
Electron
What is a circuit?
A path that allows electrons to flow
What unit is used to measure current?
Amps (A)
What unit is used for resistance?
Ohms (Ω)
What does the formula V = IR stand for?
Voltage = Current × Resistance
What is the difference between a positive and negative charge?
Positive = Lack of electrons
Negative = Excess electrons
Name the three basic parts of a circuit
Power source, conductor, load
What unit is used to measure voltage?
Volts (V)
What does resistance do in a circuit?
Slows the flow of electrons
A circuit has:
V = 12V, R = 4Ω
What is the current?
I = 3A
What happens when two like charges interact?
They repel
What is the difference between an open and closed circuit?
Open = circuit is switched off and electrons won't move
Closed = circuit is switched on and electrons will move
What does current measure?
The AMOUNT of electrons flowing past a point
In a series circuit, what happens to energy as electrons move?
It decreases (energy is used along the way)
A circuit has:
I = 2A, R = 5Ω
What is the voltage?
V = 10V
Charge that builds up on the surface of an object
What is the function of a switch?
To open or close the circuit
What does voltage measure?
The energy of the electrons (potential difference)
In a parallel circuit, what stays the same across each branch?
Voltage
A circuit has:
V = 9V, I = 3A
What is the resistance?
R = 3 Ohms
Why don't protons move to create charge?
They are fixed in the nucleus
Why won't electrons move through air in a simple battery setup?
Air is an insulator
Using the water analogy, what represents voltage?
The steepness or slope (energy of flow)
Why will electrons avoid a lightbulb if there is a shortcut wire?
They take the path of least resistance
A circuit has:
V = 40V, R = 8Ω
Find the current AND explain what happens if resistance increases.
I = 5 A
If resistance increases, current decreases