Terminology
What is a condictor and what is an insulator?
Conductors - encourage the flow of electricity
Insulators - slow down the electricity flow
What charge do electrons, protons and neutrons have?
Electrons (-) Protons (+) Neutrons are neutral
What is the purpose of a grounding wire?
Neutralizing Unbalanced Charges - Because the Earth is so big, it can easily donate or take on electrons without building up a charge
Why is no machine ever 100% effective?
No machine is ever 100% efficient because energy is always lost to things like heat, sound, etc.
What does kinetic energy measure?
The energy of movement
Static - must be charged before producing a current Current - does not require a charge
Electricity is caused by the movement of __________?
What is the differnece between a series circuit and a parallel circuit?
Series have multiple connections and parallel must have aligned wires that are hooked up to the light source
What does KWH represent?
Kilawatt hours
Is a circuit with high resistance a good conductor?
No! high resistance = poor conductor
Difference between an ammeter and a galvanometer
Galvanometer = instrument used to measure very weak electric current.
Ammeter = instrument used to measure larger currents.
What charge is being shown?
+++---
Neutral
What is the purpose of a circuit breaker?
When a circuit becomes dangerously hot, a metal strip melts and bends or breaks in order to break the circuit connection before it is too hot and becomes a fire hazard.
What are the two types of generators?
AC and DC
What are THREE factors that effect resistance in a circuit?
Cross-Sectional Area:
- larger area = less resistance
Length:
- longer wires = greater resistance
Temperature:
- higher temperature = greater resistance
Define tribocharging vs indictive charging
1. Tribocharging - rubbing (like the balloon on your hair)
2. Inductive charging - no contact required, just the presence of an electric field can charge the item.
What charge is being shown?
_+_++
Positive charge
Why are hot wires black insulated?
Why are AC generators less effective than DC generators?
Because they need to be cranked in order to gain power and they do not hold a charge for a long time.
Why did one light bulb shine brighter than the other lightbulb in a circuit? Think of resistance!
some lights could look dimmer as electrons are slowed moving through multiple loads.
What are the THREE laws of charges?
1. Unlike charges attract.
2. Like charges repel.
3. Charged objects attract uncharged (neutral) objects.
Do electrons pass through circuit wires or do protons?
Electrons
Power is measured in what?
Joules/second
Would an AC generator be measured with an ammeter or a galvanometer?
Galvanometer - because AC generators have weaker currents than a DC generator
The unit is called an Ohm and the formula for resistance is voltage/current