Energy Basics Quiz

Energy Basics

• Energy is the ability to do work or cause change, measured in Joules (J).
• Forms of Energy:
  • Radiant Energy: Travels in electromagnetic waves (light, radio waves, X-rays).
  • Chemical Energy: Stored in chemical bonds, released in reactions (burning fuel, digestion).
  • Mechanical Energy: Associated with motion or position; includes potential and kinetic energy.
  • Kinetic Energy (KE): Energy of motion; KE = 1/2 * m * v² (m = mass, v = velocity).
  • Potential Energy (PE): Stored energy due to position or condition; PE = m * g * h (m = mass, g = gravity, h = height).
  • Thermal Energy: Related to particle motion in an object; more motion = more heat.
  • Nuclear Energy: Stored in the atom's nucleus, released in fission (splitting) or fusion (combining).
  • Electrical Energy: Energy from electron flow in a circuit.
• Key Principle: Law of Conservation of Energy: Energy cannot be created or destroyed, only changed.

Electricity Fundamentals

• Electricity: The flow of electric charge (usually electrons).
• Types of Electricity:
  • Static Electricity: Buildup of charge on an object's surface.
    • Causes:
      • Friction: Charge transfer when rubbing objects (balloon on hair).
      • Conduction: Charge flow between objects touching (doorknob).
      • Induction: Charge separation without contact (balloon attracting paper).
    • Like charges repel, opposite charges attract.
  • Current Electricity: Continuous charge flow in a circuit.
    • Types:
      • Direct Current (DC): Electrons flow in one direction (batteries).
      • Alternating Current (AC): Electrons change direction periodically (homes, power grids).
• Difference: Static charges are stationary; current charges flow continuously.

Conductors, Resistors, and Insulators

• Conductor: Material allowing easy current flow (e.g., copper, aluminum, silver).
• Resistor: Material opposing current flow (e.g., light bulb filament).
• Insulator: Material resisting current flow (e.g., rubber, plastic, glass).

Circuits

• Basic Components: Power source (battery), conductor (wire), load (device), switch.
• Types of Circuits:
  • Series Circuit: Single pathway; current same everywhere, total resistance is sum of individual resistances; voltage divides proportionally across each load.
  • Parallel Circuit: Multiple pathways; voltage same across each branch, total current is sum of branch currents.

Resistance and Factors Affecting It

• Resistance (Ω): Opposition to current flow.
• Factors Affecting Resistance:
  • Length: Longer wire = higher resistance.
  • Cross-sectional area: Thicker wire = lower resistance.
  • Material: Conductors have low resistance; insulators have high resistance.
  • Temperature: Higher temperatures increase resistance.
• Ohm's Law: V = I * R (V = voltage, I = current, R = resistance).

Energy Sources

• Renewable Energy: Naturally replenishing sources.
  • Examples: Solar, wind, hydroelectric, geothermal.
  • Advantages: Clean, sustainable, reduces pollution.
  • Disadvantages: Weather-dependent, infrastructure costs.
• Non-Renewable Energy: Finite resources.
  • Examples: Coal, oil, natural gas, nuclear.
  • Advantages: Reliable, high energy output.
  • Disadvantages: Pollution, depletion, greenhouse gas emissions.
• Impacts: Renewable energy reduces pollution & climate change; non-renewable energy contributes to environmental degradation.

Key Electrical Units

• Voltage (V): Energy per unit charge (volts).
• Current (I): Charge flow (amperes).
• Resistance (R): Opposition to current (ohms).
• Power (P): Rate of energy use (watts).
• Charge (Q): Amount of electric charge (coulombs).

Hydroelectric Power

• Harnesses flowing water's kinetic energy to generate electricity. Water turns turbines, and generators convert this kinetic energy to electrical energy.

Nuclear Power

• Generates electricity through nuclear fission (splitting atoms). Uranium atoms release energy, heating water, producing steam, and consequently driving turbines.

Natural Gas Power

• Burns natural gas to produce heat, turning turbines, and generating electricity.

Wind Power

• Harnesses wind's kinetic energy; wind turbines convert wind energy to mechanical, then to electrical energy.

Solar Power

• Harnesses sunlight to generate electricity. Photovoltaic cells directly convert sunlight to electricity.

Geothermal Power

• Uses Earth's heat as an energy source.

Wave Power

• Captures energy from ocean waves.

AC vs DC

• War of Currents: Edison supported DC; Tesla championed AC, which is more efficient for long-distance transmission.

Efficiency

• Efficiency = (energy out)/(energy in).

EV vs ICE

• Electric Vehicles (EVs):
  • Pros: Environmentally friendly, zero tailpipe emissions.
  • Cons: May have limited range, higher initial cost, charging times.
• Internal Combustion Engines (ICE):
  • Pros: Widely available, generally cheaper upfront, more options for refueling.
  • Cons: Pollutant emissions, contribution to climate change, noise pollution.

Circuits (Series and Parallel):

• Series: Single path, current same throughout, total resistance is sum of individual resistances. Voltage drops add up to total.
• Parallel: Multiple paths, voltage same across each branch, total current is sum of branch currents.

Units and Measurement

• Joules (J): Measure of energy and work.
• Amps (A): Measure of electric current.
• Watts (W): Measure of power.
• Volts (V): Measure of voltage or electrical potential difference.
• Ohms (Ω): Measure of electrical resistance.
• Coulomb (C): Measure of electric charge.

Ohm's Law

• Voltage (V)=Current (I)* Resistance(R)

Renewable Energy Sources

• Energy sources that are replenished at a rate equal to or faster than their usage. (e.g., solar, wind, hydroelectric, geothermal).

Non-Renewable Energy Sources

• Energy sources that are not replenished quickly enough to replace their use (e.g., coal, natural gas, oil, nuclear).

Electricity Transmission

• Electricity generation happens at low voltage; transformers increase voltage for transmission.

Electricity Metering

• Meters track energy use for billing purposes.

Distribution Panels

• Distribute electricity throughout a home; contains circuit breakers and fuses.

Kilowatt-hour (kWh)

• A unit used to measure electrical energy use.

Kilometer

• A unit used to measure distance; equal to 1000 meters.