Electricity P1 Flashcards
What is potential energy?
The energy that an object has because of its position relative to something
What is the potential difference?
The change in potential energy per coulomb between two points
What is Ohm’s law?
At a constant temperature, current is directly proportional to the potential difference
What is resistance caused by?
Collisions between lattice ions and free electrons
What is the definition of resistance?
The opposition to the flow of charge
How does an increase in temperature effect the resistance of a metal conducting wire?
An increase in temperature causes and increase in resistance due to lattice ions vibrating more vigorously which causes an increase in the rate of collisions between the charge carriers and lattice ions
What is the power rating of a component?
Maximum amount of energy it can dissipate per second without being damaged
What is the charge capacity of a battery?
The number of coulombs that will move past a given point in a circuit before the battery dies.
What are the two main applications of superconductors?
Super efficient wires and super strong electromagnets
What are some present day applications for superconductors?
MRI scanners, Maglev trains, particle accelerators and electrical power transmissions through short wires
How is energy conserved in a circuit?
The difference in potential energy per coulomb across a cell is equal to the sum of the work done per coulomb across all components in a circuit.
How is charge conserved in a circuit?
Conservation of charge means that the number of charges entering a junction must equal the number of charges leaving the junction.
As current is the rate of flow of charge, the total current into a junction must equal the total current coming out of the junction.
If the power in a circuit was P and then the resistance was doubled, what is the new power in terms of P?
P/2
