unit v study guide electricity & magnetism answer key
TRANSCRIPT
UNIT V STUDY GUIDEElectricity & Magnetism
ANSWER KEY
1. Electricity is basically moving ____________.
• electrons
2. What is resistance?
• The opposition posed by a material to the flow of current.
3. What are the two factors of a wire that determine resistance?
• Length• Area (diameter)• Additional factors –
Temperature & Material Type.
4. Resistance is measure in what unit?
• Ohms (Ω)
5. A closed path that allows current to flow is called a __________.
• Circuit
6. Describe the difference between a parallel and series circuit?
• Circuit
7. What are examples of when you would use each type of circuit?
• Series – used for things with batteries.• Parallel – used around the
house; when things get their power from generators.
8. What is the name of a device used to prevent overheating of circuits?
• Resistor
9. What is AC?
• Alternating Current• Electron direction is constantly
flipping; electric field is changing directions.
10. What is DC?
• Direct Current• Electrons flow & electric field is
in one direction.
11. Which (AC or DC) is a battery?
• DC (Direct Current)
12. What “makes” AC?
• Generators
13. What does an electric motor do? (Hint: what form of energy does it start with and then convert to?)
• Converts mechanical energy into electrical energy.
14. What are the charges of electrons, protons, and neutrons? Why are electrons the easiest to “remove”?
• e- negative• p+ positive• n0 neutral• Electrons are easiest because
they are in the electron cloud.
15. What is the difference between conductors and insulators?
• Conductors allow the flow of electric current.• Insulators resist the flow of
electric current.
16. What is the definition of current?
• The rate at which charges move through a conductor.
17. What is the unit of current?
• Amperes / Amps (A)
18. What is the equation to calculate voltage?
•V = I·R
19. What is the voltage if the current is 10 amps and the resistance is 2 ohms?
• 20 volts
20. If 2 resistors are in series, what mathematical function must you use to determine the “equivalent resistance”?
• REQ = R1 + R2 + …
21. If one light goes and the others go out, what type of circuit do you have?
• Series
22. How can you induce current in a wire with a magnet?
• By moving the magnet back and forth (changing the electric field)
23. How would you make an electromagnet?
• By wrapping a wire supplied with current around an iron core.
24. Be able to draw series and parallel circuits.
SERIES EXAMPLE: PARALLEL EXAMPLE: