Download Electric Charge - Review Physics Unit 5 Review

Physics Unit 5 – Electric Charge – Review
Name:
Conceptual Questions:
1.
_____________________ are the carrier of negative electric charge and ______________________ are the carrier of positive electric charge.
2.
Two positively charged objects will _____________________ each other, two negatively charged objects will ________________ each other, and a positively
charged object and a negatively charged object will _____________________ each other.
3.
Why is it wrong to say that a positively charged object has “gained protons”?
4.
What property defines an electrical conductor?
6.
You have an exposed copper wire. Would wrapping a piece of aluminum around the wire protect a person who grabs the wire from getting shocked? Explain.
7.
Touching a charged object to another object, allowing charge to flow between them, is charging by ___________________. Forcing charge into or out of another
object without touching is charging by ___________________
8.
How could you induce a positive charge into a metal ball if all you have is a negatively charged object?
9.
If the electric force is so much stronger than gravity, why don’t we feel it around us all the time like we do gravity?
10.
A charged object would feel a weaker force if placed 10 m from a +2 C point charge than if placed 5 m from a +2 C point charge. Why is this?
11.
What does field line density indicate about an electric field?
12.
What does field line direction indicate about an electric field?
13.
Bringing two charged objects four times closer will increase the force between them by ____________________ times.
14.
Combine the equation for the electric field produced by a point charge and the equation for the force felt by a charge in an electric field into one equation that
solves for force. (This equation is called Coulomb’s Law)
17.
Draw field lines for a -1 C charge near a +2 C charge.
)
5.
What property defines an electrical insulator?
16. Draw field lines for a -1 C charge near a -1 C charge.
17. For questions 15 and 16, where are the
fields the strongest and where the fields
the weakest? (write an S for strong and
W for weak).
Calculation Questions:
18. Having 6.52x109 excess electrons would give an object what charge?
19. A complex polyatomic ion with 326 protons and 323 electrons would have
what charge?
20. What strength charge would feel a force of 1.7 N in a 3972 N/C electric field?
21. If a 240 N/C electric field were to interact with a -1.2 µC charge, what force
would the charge feel?
22. What is the electric field strength 0.56 m away from a -2.5 nC point charge?
23. If a +6.2 pC charge were placed at the location given in the previous question,
what force would it feel? (Also say if the force is attractive or repulsive).
23. What is the linear charge density of a wire that produces an electric field of 640
N/C at a distance of 82 cm?
24. If a +4.2 µC charge were placed at the location given in the previous question,
what force would it feel? (Also say if the force is attractive or repulsive).
26. If a +284 nC point charge passes over a plate with a charge per area density of
+144 nC/m2, what force will it feel (include if it is attractive or repulsive)?
27. How many excess protons would be on the plate in the previous question if it
were 6.7 m2?