Current Electricity Concepts
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Questions and Answers

What is the primary function of a fuel cell?

  • To recycle batteries
  • To recharge electric cells
  • To convert chemicals into electricity (correct)
  • To store energy for later use

    • What term is used to describe electric charges that flow through a conductor in a controlled way?

  • Chemical Electricity
  • Static Electricity
  • Magnetic Electricity
  • Current Electricity (correct)

    • Alternating current (AC) flows in one direction through an electric circuit.

    False

    Primary cells can be recharged multiple times.

    <p>False</p> Signup and view all the answers

    What are the two forms of current electricity?

    <p>Direct Current (DC) and Alternating Current (AC)</p> Signup and view all the answers

    What is the term for a combination of two or more electric cells?

    <p>battery</p> Signup and view all the answers

    The positive terminal of a battery is located at the ______.

    <p>top</p> Signup and view all the answers

    An electric circuit requires a source of energy, a load, conducting wires, and sometimes a ______.

    <p>switch</p> Signup and view all the answers

    Which of the following is a disadvantage of hydro-electric generation?

    <p>It can damage ecosystems by flooding</p> Signup and view all the answers

    Match the following components of an electric circuit with their descriptions:

    <p>Energy source = Provides the electrical power Load = Transforms electrical energy into other forms Conducting wires = Connects all circuit components Switch = Controls the flow of electricity</p> Signup and view all the answers

    Which type of current is produced by an electric cell?

    <p>Direct Current (DC)</p> Signup and view all the answers

    Match the type of generation with its description:

    <p>Hydro-electric = Uses the energy of falling water Tidal generation = Uses cyclical movement of ocean tides Wind generation = Uses large blades mounted on tall towers Solar generation = Converts sunlight into electricity</p> Signup and view all the answers

    What is produced when hydrogen and oxygen react in a fuel cell?

    <p>water</p> Signup and view all the answers

    An open circuit allows electricity to flow.

    <p>False</p> Signup and view all the answers

    Electricity is produced when one type of energy is converted into ______.

    <p>electrical energy</p> Signup and view all the answers

    What is electrical energy?

    <p>Energy provided by the flow of electrons in an electric circuit.</p> Signup and view all the answers

    Electric cells convert ______ energy into electrical energy.

    <p>chemical</p> Signup and view all the answers

    Electricity can travel long distances to where it is needed.

    <p>True</p> Signup and view all the answers

    Why is Alternating Current (AC) used in electric generating stations?

    <p>It is more efficient for long-distance distribution.</p> Signup and view all the answers

    What is a primary disadvantage of wind generation?

    <p>Requires strong constant winds</p> Signup and view all the answers

    What is a major drawback of wind energy generation?

    <p>Wind isn't always blowing</p> Signup and view all the answers

    Solar panels operate independently of an electrical grid.

    <p>True</p> Signup and view all the answers

    What does an Energuide label provide to consumers?

    <p>An estimate of how much electrical energy the appliance will use in one year.</p> Signup and view all the answers

    ______ is a renewable energy resource that uses heat from the Earth's crust.

    <p>Geothermal energy</p> Signup and view all the answers

    Match the following energy types with their characteristics:

    <p>Wind Energy = Relies on the presence of wind Solar Energy = Utilizes photovoltaic cells Geothermal Energy = Uses heat from the Earth's crust Biomass Energy = Involves organic matter</p> Signup and view all the answers

    What is a common disadvantage of using solar energy?

    <p>It is very expensive</p> Signup and view all the answers

    Biomass generation contributes to greenhouse gas emissions.

    <p>True</p> Signup and view all the answers

    What is a 'phantom' load?

    <p>Small amounts of energy used by appliances even when they're off.</p> Signup and view all the answers

    Thermal generation uses heat to produce __________.

    <p>electricity</p> Signup and view all the answers

    Which of the following is a benefit of biomass generation?

    <p>Organic material is available everywhere</p> Signup and view all the answers

    What is a primary disadvantage of burning fossil fuels?

    <p>Releases CO2 which contributes to global warming</p> Signup and view all the answers

    Nuclear power generates greenhouse gases.

    <p>False</p> Signup and view all the answers

    What is measured in watts (W)?

    <p>Electrical power</p> Signup and view all the answers

    A kilowatt-hour represents _____ watts of energy used over one hour.

    <p>one thousand</p> Signup and view all the answers

    Match the device with its efficiency:

    <p>Incandescent bulb = 60W Compact fluorescent bulb = 18W LED bulb = 10W Old clothes dryer = 800 kWh per year</p> Signup and view all the answers

    How do older appliances generally compare to newer ones in terms of energy use?

    <p>They use more energy for the same task</p> Signup and view all the answers

    Efficiency can be greater than 100%.

    <p>False</p> Signup and view all the answers

    What time frame is electricity most expensive in Ontario?

    <p>7 AM to 7 PM on weekdays</p> Signup and view all the answers

    The _____ of electrical devices refers to how much useful energy is produced compared to the energy supplied.

    <p>efficiency</p> Signup and view all the answers

    Which of the following is a pro of using nuclear power?

    <p>Generates energy without greenhouse gases</p> Signup and view all the answers

    Study Notes

    Current Electricity

    • Current electricity refers to the controlled flow of electric charges (electrons) through a conductor such as metal wires (e.g., copper or aluminum).
    • This flow is provided by batteries or an electrical generating station (power outlets).
    • Electronic devices require electron flow to function.
    • The continuous path for electron flow is an electric circuit.

    Direct Current (DC)

    • DC is a flow of electrons in one direction through an electric circuit.
    • DC is produced by electric cells, used to power small devices.

    Alternating Current (AC)

    • AC is a flow of electrons that reverses direction in the electric circuit.
    • AC is produced by generating stations for power lights and larger devices.
    • AC is more efficient than DC for long-distance electrical energy distribution.

    Electric Circuits

    • An electric circuit includes:
      • An energy source (e.g., battery or generating station).
      • A load, which transforms electrical energy into another form (e.g., heaters, lamps, fans, computer parts).
      • Wires that connect all circuit components.
      • A switch to control the flow of electrons (sometimes).
    • An open circuit has a broken connection, preventing electricity flow.
    • A closed circuit has all connections, enabling electricity flow.

    Electrical Energy Sources

    • Electric Cells: These portable devices convert chemical energy into electrical energy.
      • They have two electrodes (positive and negative terminals).
      • Primary cells cannot be recharged; secondary cells can.
      • Batteries are combinations of multiple cells.
    • Fuel Cells: Fuel cells provide a continuous supply of chemicals to generate electricity, allowing for longer operation compared to conventional cells.
      • Example: Hydrogen fuel cells convert hydrogen and oxygen into water, producing electricity as a byproduct.

    Generating Electricity

    • Electricity is produced when one form of energy is converted into electrical energy.
    • Generating stations convert mechanical energy into electrical energy.
    • External forces (like water flow or wind) spin turbines, which rotate coils in generators that create electron flow.
    • This process is controlled for regulated and long-distance power delivery.

    Renewable Energy Generation

    • Water Generation (Hydroelectric): The energy of falling water is used to turn turbines to produce electricity.
      • This is renewable (always available).
      • Dams are often used to store water for steady power generation.
    • Wind Generation: Wind turbines turn generators to produce electricity.
      • They do not pollute air or water; they can be located close to where the power is needed reducing transmission lines.
    • Solar Generation: Photovoltaic (PV) cells directly convert light to electricity.
      • Renewable (sunlight is always available).
      • Not very efficient yet.

    Geothermal Energy

    • Ground-sourced geothermal energy involves circulating fluid through subterranean pipes to extract heat from Earth's crust for electricity generation.
    • The Earth's core supplies a continuous temperature creating a sustainable source of energy.

    Biomass Generation

    • Biomass generation uses organic matter (plant/animal material, wood, straw, manure, etc.) to produce electricity.
    • These resources are renewable and can be replenished.
    • Can be converted to a variety of fuels.

    Non-Renewable Energy Generation

    • Non-renewable sources use resources that will eventually run out (e.g., fossil fuels like coal, oil, and natural gas; nuclear uranium).
    • These processes also produce pollutants (e.g., CO2, acid rain, greenhouse gases).
    • They use thermal processes to produce steam that generate electricity.

    Electrical Power and Efficiency

    • The rate at which electricity is produced or consumed is measured in watts (W).
    • Kilowatt-hours (kWh) are also used (one thousand watts operating for one hour).
    • Efficiency is the ratio of useful energy produced compared to the energy input.
    • Inefficiencies result in energy loss due to various factors, ideally always less than 100%.

    Cost of Electricity

    • Electricity costs vary regionally and depend on time of day/week (off-peak, mid-peak, on-peak).
    • The cost of operating a device can be calculated using the equation (power used (kW) × time (hours) × cost per kWh).

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    Current Electricity (PDF)

    Description

    This quiz covers key concepts related to current electricity, including the definitions and differences between direct current (DC) and alternating current (AC). Additionally, it explores the structure and components of electric circuits. Test your understanding of how electric charge flows and how it powers devices!

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