Insulators and Conductors. Electric Circuit Current provided by battery flows through wire, into the light bulb, through another wire, and back to the battery. Current: flow of electrons. Battery. Electric lamp (glowing). Electric lamp (not glowing). Insulator doesn’t let electrons flow.
Electric lamp (glowing)
Electric lamp (not glowing)
doesn’t let electrons flow
lets electrons flow
Zero Resistance Infinite conductivity
Only at very low Temperature
High-Voltage Transmission Lines:
Up to 765,000 Volts
Wires are Copper
Insulators are ceramic
(they used to be glass).
Computers have printed circuit boards with copper lines connecting different Silicon chips.
High-Voltage Breakdown Insulators
Silicon is a semiconductor it can conduct or insulate
Free electronsfrom outer shells of metal atoms can move throughout material
Metal ions (+) remain stationary
Conductors let electrons go. They travel anywhere in the material.
Insulators let electrons flow like dogs running free
There are NO free electrons, electrons are shared between atoms in bonds.
Insulators hold electrons close like a dog on a leash
Metal ions (O) remain stationary
Conductors let electrons flow like dogs running free
Resistance: is like resistance to water flow in a hose. Larger diameter hose -less resistance, longer hose –more resistance
Voltage like pressure, current like flow
R = V / I
R = ( x L) / A
R - Resistance - Density L - Length A - Area