Electricity Flashcards
What are the factors affecting resistance?
- Type of material
- Cross sectional area: thickness
- Length: as it increases so does resistance
- Temperature: increase in temp=increase in resistance
What is AC?
Alternating current- a flow of electrons that alternates in direction (wall outlet)
What is direct current?
Direct current- a flow of electrons in one direction (batteries)
What are the 9 ways of generating electricity?
Wind energy, solar energy, hydropower, natural gas, coal, petroleum, biomass, geothermal, uranium
What are 2 advantages and 2 disadvantages about solar energy?
Advantages:
- Non-polluting
- Systems last 15-30 years
Disadvantages:
- Expensive
- Needs sunny weather
What are 2 advantages and 2 disadvantages about wind energy?
Advantages:
- No emissions
- Affordable
Disadvantages:
- Requires wind
- Possible health risks
What are 2 advantages and 2 disadvantages about Hydropower?
Advantages:
- Reliable
- No emissions
Disadvantages:
- Environmental impacts (Dam)
- Expensive
What are 2 advantages and 2 disadvantages about Natural gas, Biomass, Coal and Petroleum energy?
Advantages:
- Widely available
- Abundant supplies
Disadvantages:
- Emissions
- Transportation is expensive
What are 2 advantages and 2 disadvantages about Geothermal energy?
Advantages:
- Efficient
- Low cost
Disadvantages:
1. Expensive to start up
What is an advantage and a disadvantage about uranium energy?
Advantage:
No emissions
Disadvantage:
Waste
What is resistance? Where does it occur?
Resistance is anything that impedes, slows or resists the flow of electrons in a circuit. It occurs everywhere in the circuit but the most at the load
What is the equation for Power?
P= V x I
P= power (w)
V= voltage (v)
I=current (a)
What is the equation for current?
I= Q / T
I=current(a)
Q= coulombs of charge (c)
T= time (s)
What is the equation for consumption?
E= P x T
E= energy consumption (kW•h) P= power rating (w) T= time (s)
What is the equation for resistance?
R= V / I
R= resistance (ohms) P= potential difference (v) I= current (a)
What is the equation for efficiency?
EE= EO / EI
EE= efficiency (%) EO= energy output (j) EI= energy input (j)
*output is never more than input, efficiency is never more than 100%
What is the equation for voltage?
V= E / Q
V= potential difference (v) E= energy (j) Q= coulombs of charge (c)
What is the equation for cost?
C= E x R
C= cost ($) E= energy (j) R= coulombs of charge (c)
What is the ability to do work?
Energy [Joules [J]]
What is the rate at which electric energy is produced or consumed over time?
Electric power
P– Watts or kilowatts
What is: “how much electricity you use and are charged for”?
Electrical consumption
What does electrical consumption depend on?
- Duration of use
2. Number and efficiency of electrical devices using
