Charges
What are the parts of an atom and their charges?
Proton - positive
Electron - Negative
Neutron - Neutral
Give an example of static you see in nature.
Lightning
What is the difference between an insulator and a conductor?
Insulator doesn't allow electricity to flow, conductor does.
What are the 4 main parts of a circuit?
battery, wire, load (bulb, device, etc.), switch
What do Amperes (Amps) measure?
The rate of flow of electricity (number of electrons in an electrical current).
What is the Law of electric charges?
Like charges repel. Opposite charges attract.
Why should you not go swimming outside when it is thunder and lightning out?
Water is a conductor of electricity. If the lightning strikes the water while you are in it, the electricity can travel through the water, to your body and shock you.
Give an example of an insulator and a conductor.
Insulator: rubber, glass, sand, plastic, dry air, etc.
Conductor: metals, water, etc.
What is the difference between an open circuit and a closed circuit?
Closed: electrons flow and device gets power
Open: no flow of electrons, no power to device
What do Watts (W) measure?
The amount of power a device uses per hour.
How do charges play a role in static electricity?
When two materials rub together, electrons from one are transferred to the other. Temporary build up of electrons.
What does an electrostatic series show you?
When two materials are rubbed together, which one will be more negatively charged and which one will be more positive. Which tends to gain vs lose electrons.
What is the difference between alternating current (AC) and direct current (DC)?
DC flows in one direction, AC periodically reverses direction.
What are 2 advantages to a parallel circuit?
- doesn't lose any power when more bulbs are added
- if one bulb goes out the others keep working
What does Voltage (V) measure?
Measure of electrical pressure, force or push on electrons in a circuit.
What is electric discharge?
When a static charge builds up so much, it must be released. Release of electrons as a shock.
Why does rubbing a balloon on your hair cause it to stand up?
The friction causes a transfer of electrons from your hair to the balloon. Your hair is now more positively charged and the balloon more negative. Opposite charges attract.
Bob used 362KWh of electricity for the month of Feb. If the cost for electricity is 0.1625cents/KWh, how much did this cost him?
$58.83
Explain the importance of a resistor in a circuit.
To control the electrical current so correct amount is delivered to what is being powered. If too much, the device will not work correctly.
What do Ohms measure?
The amount of electrical resistance that is being applied.
Describe how electricity flows from a battery and explain why.
Why is it called "static" electricity.
It is "static" because the charges are stationary, not flowing like in current electricity. The accumulate and remain on the surface of an object.
Sue has 10 lightbulbs in her house. If each bulb uses 0.3KW/hr and she leaves them on for 8 hours while she is at work, how much would this cost her? (cost of electricity is 0.1625cents/KWh)
$3.90
Explain how an incandescent light bulb works.
When electricity passes through the filament of the bulb, it meets resistance (more difficult to pass through). This resistance creates heat energy. This heat energy causes the filament to glow white-hot.
A 4V potential difference is applied across a 8Ω resistor. What is the current that flows into the resistor?
I=V/R I=4/8 I=0.5 Amps of current.