Electrical Concepts and Ohm's Law Quiz

Ohm's Law and Power Formulas

• Ohm's Law: V = IR; I = V/R
  • V (voltage) is measured in Volts.
  • I (current) is measured in Amperes.
  • R (resistance) is measured in Ohms.
• Power Formula: P = IV; P = I²R; P = V²/R
  • P (power) is measured in Watts.

Kirchhoff's Rules

• Kirchhoff's Loop Rule: The sum of voltages around a closed loop is zero.
• Kirchhoff's Junction Rule: The sum of currents entering a junction equals the sum of currents leaving the junction.

Electrical Devices

• Motor: Converts electrical energy to mechanical energy.
• Generator: Converts mechanical energy to electrical energy.
• Step-Down Transformer: Decreases voltage. Output voltage is lower than input voltage. Fewer secondary coils than primary coils.
• Step-Up Transformer: Increases voltage. Output voltage is higher than input voltage. More secondary coils than primary coils.
• Back EMF: Voltage opposing the motor's rotation.

Basic Electrical Concepts

• Voltage: Electric potential difference or charge imbalance, causing current flow.
• Resistance: Opposition to current flow.
• Ohm's Law: Mathematical relationship among voltage, current, and resistance.
• Ammeter: Measures current. Connected in series.
• Electromagnetic Induction: Current generation in a conductor due to a changing magnetic field.

Transformer Details

• Transformer Output Voltage: Determined by the input voltage and the ratio of primary to secondary coil numbers.
• Transformer Function: Electrical device that increases or decreases voltage using coils wrapped around a shared iron core.

Diode and Ohmic Materials

• Diode: Non-ohmic conductor with a non-linear voltage-current relationship.
• Ohmic Materials: Constant resistance, linear voltage-current relationship.
  • Examples: Resistor, lamp

Electric Circuit

• Electric Circuit: Occurs when an electrical conductor is in a battery.

Energy Sectors and Resources

• Energy Use Sectors: Industrial, commercial, residential, transportation.
• Load Management: Process tracking and balancing energy supply and demand.
• Non-renewable Energy Sources: Oil, natural gas, coal. (Fossil fuels)
• Renewable Energy Sources: Solar energy, solar power, wind energy.
• Non-renewable Energy Impacts: Acid rain, air pollution, climate change.
• Fossil Fuels: Primary global energy source.
• Fossil Fuel Exploration Costs: Significant cost.
• Non-renewable Resource Characteristic: Limited availability.