Chapter 23: Electric Current

electric currrent

flow of charged particles

electric current in metal wires

conduction electrons are charged carriers that are free to move throughout atomic lattice; protons are bound within the nucleus

electric current in fluids

positive ions and electrons constitute electric charge flow

electric current

charge flows through a circuit, voltage is established across a circuit; measured in amps

electric resistance

current is dependent on voltage and resistance (in Ohms); resistors are circuit elements that regulate current inside electrical devices

Ohm’s Law

relationship between voltage, current, and resistance

current = V/R

voltage = IR

direct current

Edison, flows in one direction, e- always move from negative terminal to positive terminal

alternating current

Tesla, e- in the circuit are moved in one direction and then the opposite (to and fro), happens by alternating polarity of voltage at the generators

semiconductors

materials that can alternate between being conductors and insulators (geranium, silicon)

superconductors

materials with zero electrical resistance to the flow of charge

diode

tiny electronic device that acts as a one-way valve to allow electron flow in only one direction

electric shock

damaging effects of shock result from current passing through the body

electric power

IV

series

single pathway circuit for e- flow between terminals of power source

- total resistance = individual resistance

- total voltage divides among each device

- current = voltage supplied by the force divided by total resistance

- if one fails, all fail

parallel

circuit that forms branches, each of which is a separate path for e- flow

- total current = sum of all currents

- more branches = less resistance

- total current divides among branches