2.1 - Controlling the Flow of Electrical Current Flashcards
What determines if a substance is a better insulator or conductor?
The atomic structure of a substance determines if it is a better insulator or conductor.
True or false:
In an insulator, electrons are tightly bound to the nuclei.
True
What properties of conductors make them conductors?
In a conductor, electrons are free to move around.
When electricity is added to a conductor, electrons move towards the positive terminal
What are superconductors? Provide an example.
Have no resistance to electron flow.
- Ex. Mercury at absolute zero
What is a resistor?
A conductor that allows electrons to flow, but provides some resistance, limiting the amount of current
What is resistance?
A measure of how difficult it is for electrons to flow through a substance (measured in ohms/Ω)
What is the result of an increase in resistance?
The more resistance, the greater the energy gain from each passing electron because the electrons are using more energy to pass through the resistor. This energy is radiated to the surroundings as heat or light.
- Ex. A light bulb filament
How are resistance and conductivity related?
Resistance and conductivity are inversely related: the greater the resistance, the lower the conductivity, and vice versa.
Can solutions be resistors?
Yes
What is a switch?
Allows or stops the flow of electricity
When open, there’s no flow- conductors separated
When closed, there’s flow- conductors together
What is a variable resistor or rheostat?
Can be used to adjust the resistance gradually, changing the amount of current that flows through the circuit
- Ex. Light dimmer or volume control knob
