PHYSICS ELECTRICITY + EARTH

Current

Flow rate of electric charge.

Voltage

potential difference between two points in a circuit.

Resistance

Opposition to current flow.

Ohm’s Law

V = IR relationship.

Open Circuit

Broken path; no current.

Closed Circuit

Complete path; current flows.

Battery

Stores chemical energy; provides voltage.

Semiconductor

conductivity between conductors and insulators.

Potentiometer

adjust current or voltage in a circuit.

Multimeter

Measures voltage, current, and resistance.

Oceanic Crust

Thin, dense lower crust.

Mantle

Layer below crust; semi-fluid + rigid parts.

Outer Core

Liquid metal layer; makes magnetic field.

Inner Core

Solid iron-nickel center.

Density

Mass per volume; controls Earth layering.

Lithosphere

Rigid crust + upper mantle.

Convection Currents

Mantle heat cycles that move plates.

Divergent Boundaries

Plates separate; new crust forms.

Convergent Boundaries

Plates collide; mountains or subduction.

Transform Boundaries

Plates slide past; earthquakes.

Subduction Zones

Ocean plate sinks; volcanoes form.

Mid‑Ocean Ridges

Underwater mountains from divergence.

Earthquakes

Ground shaking from plate motion.

Volcanoes

Magma reaches surface.

Ring of Fire

Pacific zone of quakes + volcanoes.

Pangea

Ancient supercontinent.

Fossil Evidence

Matching fossils show continents once connected.

Hot Spots

Fixed magma plumes forming volcanic islands.

Continental Crust

Thick, less-dense upper crust.