Motors
It converts electrical energy into mechanical energy by using electromagnetic interactions between the stator's magnetic field and the rotor's current-carrying windings.
DC Electric motor
Is low-cost renewable energy the answer or not?
Renewables are part of the solution due to their declining costs and environmental benefits, but challenges include:
Is a turbine used to generate electricity similar to a jet engine in an airliner?
Yes, both use rotating blades to extract energy from a moving fluid (air or steam).
What is an example of a dirty source of energy? WHY?
COAL, oil, unregulated natural gas because of its High Carbon Emissions, air pollution, and low efficiency
In what things do we use DC electric motors?
DC motors are widely used in fans, toys, electric vehicles, conveyors, and various other machines requiring precise speed and torque control.
How much do changing natural gas and coal prices impact the cost of electricity?
Electricity prices are highly sensitive to fuel prices, especially in areas where coal and gas dominate the energy mix.
Why is coal-fired power generation so inexpensive if its efficiency is so low?
Coal plants are cheap because coal itself is abundant and inexpensive, and the infrastructure is well-established. However, this low cost often ignores externalities like pollution and health impacts.
Explain Ohm’s Law in your own words.
Ohm’s Law describes the relationship between voltage, current, and resistance in an electrical circuit. It states that the current (I) flowing through a conductor is directly proportional to the voltage (V) across it and inversely proportional to the resistance (R).
What are some advantages of an electric motor?
High Efficiency, Versatility, Reliability, Clean and Environmentally Friendly, Quiet Operation, Scalability
What’s the best way to produce electricity? Explain “best?”
The “best” way to produce electricity depends on criteria like cost, reliability, environmental impact, and scalability.
How high is voltage in a transmission line?
Transmission lines: 69 kV to over 765 kV (kilovolts), depending on the distance.
What is the difference between electrical power and electrical energy?
Electrical Power: The rate at which electrical energy is transferred or consumed, measured in watts (W). Formula: P=V×IP = V \times IP=V×I.
Electrical Energy: The total amount of power used over time, measured in watt-hours (Wh) or kilowatt-hours (kWh). Formula: E=P×tE = P \times tE=P×t.
What is the difference between an AC and DC motor?
DC Motor: Powered by direct current, which flows in one direction
AC Motor: Powered by alternating current, where the flow of electricity periodically reverses direction.
Approximately how much energy is lost in power conversion? Why?
Energy losses during power conversion vary:
Name an unreliable source of energy
Wind power, solar power,
Name three insulators
Rubber, glass, plastic
How do DC electric generators work?
DC generators work on Faraday’s law of electromagnetic induction. When a conductor (like a coil of wire) moves through a magnetic field, it induces an electric current. In a DC generator, a commutator rectifies the alternating current generated by the rotating coil, producing direct current.
How does cogeneration use recycling to recover wasted energy?
Cogeneration, or combined heat and power (CHP), captures and repurposes the waste heat from electricity generation (e.g., in industrial processes) to produce additional energy or heat buildings. This improves efficiency significantly.
Describe the electricity grid
The electricity grid is a network of:
How are DC voltage, current and resistance are similar to a waterfall?
Voltage: Similar to the height of the waterfall, representing the potential energy difference that drives the flow.
Current: Analogous to the volume of water flowing, representing the rate of charge flow.
Resistance: Comparable to obstacles in the riverbed that slow the water flow.