Exam Study Notes: Natural Resources, Electricity, Electrostatics, Circuits, and Electromagnetism

• Essential Understandings- Natural Resources and Electrical Generation are connected. Mineral resources are products of magmatism, tectonism, and erosion/deposition. Energy in Earth systems is converted to electricity through specific mechanisms; electricity is generated by induction, involving a series of energy conversions from natural resources.

Electrostatics

• Charging Processes- Objects become charged via contact, friction (triboelectric effect), or induction.

• Electric Field Lines- Model electric field force; density indicates strength, direction indicates force on a positive charge.

• Law of Attraction/Repulsion- Like charges repel; opposites attract. Coulomb's Law: F = k \frac{q1 q2}{r^2}, where F is the electrostatic force, k is Coulomb's constant, q1 and q2 are charges, and r is the distance.

• Potential Energy Difference- Potential difference is the work needed to move charge between two points: V = \frac{W}{q}, where V is voltage, W is work, and q is charge.

Current Electricity

• Charge Movement- Charged particles move due to differences in electrical potential energy.

• Ohm's Law- V = IR, relating voltage, current, and resistance, where V is voltage, I is current, and R is resistance.

Circuits

• Schematic Diagrams- Symbols represent circuit components and connections.

• Series and Parallel Circuits- Series Circuits- Components connect end-to-end; same current flows through all. Total resistance: R{total} = R1 + R2 + … + Rn

  • Parallel Circuits- Components connect across each other; voltage is the same across all. Total resistance: \frac{1}{R{total}} = \frac{1}{R1} + \frac{1}{R2} + … + \frac{1}{Rn}

• Electrical Power- P = IV, where P is power, I is current, V is voltage. Also, P = I^2R or P = \frac{V^2}{R}.

• Energy Use and Cost- E = Pt, where E is energy, P is power, and t is time. Cost is based on energy use and unit cost.

Electromagnetism

• Magnetic Field Lines- Model magnetic fields; direction indicates north pole direction, density indicates strength.

• Electric Current and Magnetic Fields- Electric current creates magnetic fields. Right-Hand Rule relates current and field direction.