Unit 5 - Electricity & Magnetism Flashcards
(11 cards)
Conductors
Solids in which change flows freely
Insulators
Solids that do not easily allow the flow of change
Ohm’s Law
The potential difference between any 2 points in a conductor varies directly as the current between the 2 points (assuming a roughly constant temperature)
Law of conservation of energy for a circuit
As charge moves through an electric circuit they gain energy as they pass through sources (batteries) and lose energy in loads (resistors), but the total energy gained in one trip around a circuit equals to the total energy lost.
Law of conversation of charge for a circuit
Electric change s not created nor lost in an electric circuit. It also doesn’t accumulate at any point in the circuit
Kirchhoff’s Voltage Law (KVL)
Around any complete path through an electric circuit (a “loop”), the sum of the increases in electric potential (usually source) is equal to the sum of the decreases in electric potential (usually voltage drops due to loads). “The total of the potential difference around a complete loops is zero.”
Kirchhoff’s Current Law (KCL)
At any junction point in an electric circuit (also called a node), the total electric current into the junction is equal to the total electric current out
Induced magnetism
Certain materials become magnetized by running them across in existing magnet or placing them in a magnetic field. This is called induced magnetism.
Motor Principle
Moving charges in a magnetic field will be subject to force. The force perpendicular to both the direction of the current and the magnetic field. The strength of the force depends on both the field strength and the rate of he charge flow (the current).
Faraday’s Law of Electromagnetic Induction
If a conductor is in the presence of a moving or charging magnetic field, a current is induced in the conductor
Lenz’s Law
The induced current must have a direction such that the induced magnetic field opposes the motion that is inducing the current in the first place.
