Physics Short Answers UNIT TEST Flashcards
(40 cards)
What are the 3 types of Charges that can we created on an Object?
Positive, Negative, Neutral
What Type of Charge moves through an Object?
Electrons (negative charges) move through objects.
What Type of Charge moves through a Circuit?
Electrons (negative charges) move through circuits.
What are the 4 points of the Law of Electrostatic
- Like charges repel.
- Opposite charges attract.
- Neutral objects are attracted to charged objects.
- Only electrons move.
Why don’t Electrons move through Insulators?
Because the electrons in insulators are tightly bound to their atoms and not free to move.
What is the purpose of an Electroscope
To detect the presence and type of electric charge on an object.
What is the Electrostatic Series
A list of materials ranked by their ability to gain or lose electrons through friction.
How does Matter become Negatively Charged?
By gaining electrons (negative)
How does Matter become Positively Charged?
By losing electrons (positive).
What is Charging by Friction?
When two neutral objects are rubbed together, electrons are transferred from one to the
other, resulting in one becoming positively charged and the other negatively charged.
If a wool sweater is pulled over a cotton shirt and they rub together, explain what will happen?
Discuss what charge each material recieves, what type of charge occured, and how will the materials behave near one another after charging has occured
Wool and cotton exchange electrons. Based on the electrostatic series, wool loses electrons and becomes positively charged, while cotton gains electrons and becomes negatively charged. This is charging by friction. The two will then attract each other due to opposite charges
Describe charging by contact.
A charged object touches a neutral object and transfers electrons. Both objects end up with the same type of charge.
Describe charging by induction. What does induction mean?
Charging by induction occurs without contact. A charged object brought near a neutral one causes a separation of charges. The object remains overall neutral unless grounded.
Why is the earth a good ground?
Because it can easily accept or supply electrons due to its vast size and conductivity.
Provide examples of how static can affect our everyday lives.
- Getting shocked after walking on carpet
- Clothes clinging together in a dryer
- Hair standing up after removing a hat
Briefly explain how lightning forms.
- Friction inside storm clouds causes electrons to move.
- The bottom of the cloud becomes Negative, while the top is Positive.
- The ground becomes positively charged due to induction.
- When the charge difference is too great, electrons jump to the ground, creating a discharge.
Compare Static and Current Electricity.
Static electricity: Charge is stationary (an electric charge that is at rest, meaning it has no velocity or movement), builds up on surfaces.
Current electricity: Electrons flow continuously through a circuit.
What is current? Explain. What instrument is used to measure it?
Current is the flow of electric charge (electrons). It’s measured in amperes (A) using an
ammeter
(I)
What is a circuit? What happens to current in a circuit?
A circuit is a closed path for electrons to flow. Current flows continuously if the circuit is closed.
What are the four main parts of a circuit?
- Energy source
- Conductors
- Load
- Switch
What is the purpose of a load?
To convert electrical energy into other forms (light, heat, motion).
What is an open and closed circuit?
Open circuit: path is broken, no current flows.
Closed circuit: complete path, current flows.
Be able to use circuit symbols to draw series and parallel circuits.
Review Notes
What does it mean for a load to be connected in series? In parallel?
Series: loads are on one path—same current through all.
Parallel: each load has its own path—voltage is the same across each.
