Unit 8 Review

Answers hidden in pop-up menu.

 

1. Which of the following are true of static charges? (Circle all that are true.)

  1. Like charges repel.
  2. Like charges attract.
  3. Opposite charges repel.
  4. Opposite charges attract.
  5. A positively charged object has lost electrons.
  6. A positively charged object has gained protons.
  7. A negatively charged object has lost protons.
  8. A negatively charged object has gained electrons.

 

2. The charge of one electron is -1.6 X 10-19 Coulombs. If a neutral object loses 1.5x106 electrons, then what will be its charge?

3. A negatively-charged balloon is held above (without touching) a neutral electroscope. The presence of the nearby balloon causes the needle of the electroscope to deflect.

Draw the charges on "induced" or "polarized" neutral electroscope below. Explain how the balloon has induced the temporary charge upon the electroscope.

 

Consider the negatively charged electroscope at the right for review questions #4 and #5.

4. If a negatively charged balloon is brought near the top of the electroscope, the deflected straw will:

  1. not move at all.
  2. be deflected more.
  3. be deflected less.

 

 

5. If a positively charged balloon is brought near the top of the electroscope, the deflected straw will:

  1. not move at all.
  2. be deflected more.
  3. be deflected less.

 

 

6. The outer electrons in metals are not tightly bound to the atomic nuclei. They are free to roam in the material. These materials are good

  1. conductors.
  2. insulators.
  3. for nothing.

 

For questions #7 and #8, consider the following situation. Connor Duct (Con to his friends) takes a positively charged metal tube and touches a metal sphere on an insulated stand as shown at the right. Draw the direction of electron flow.

7. Electrons will flow until the two objects have equal ____.

  1. charge.
  2. electric potential.
  3. potential energies.

 

 

8. The charge on the metal sphere will end up ___.

  1. neutral
  2. negative
  3. positive

 

 

9. If an electroscope, charged up with excess negative charge, is touched and grounded, then it will end up with ___ charge.

  1. neutral
  2. negative
  3. positive

 

 

10. What will be the charge of the following sphere in step e if steps a - d are followed?

Explain how the object acquires this charge.

 

 

11. Charge carriers in a metal are electrons rather than protons because electrons are __________.

  1. loosely bound
  2. lighter
  3. far from a nucleus
  4. all of the above
  5. none of the above

 

12. Two like charges ________.

  1. attract each other
  2. repel each other
  3. neutralize each other
  4. have no effect on each other
  5. must be neutrons

 

13. When the distance between two charges is halved, the electrical force between the charges _____.

  1. quadruples
  2. doubles
  3. is reduced by 1/4
  4. halves
  5. none of these

 

14. If you comb your hair and the comb becomes positively charged, then your hair becomes _______.

  1. positively charged
  2. negatively charged
  3. uncharged

 

15. A negatively charged rod is brought near a metal can that rests on a wood table. You touch the opposite side of the can momentarily with your finger. The can is then _______.

  1. positively charged
  2. negatively charged
  3. uncharged
  4. charged the same as it was

 

16. Two charges have a force of -55 Newtons. The force is ___.

  1. attractive
  2. repulsive
  3. either attractive or repulsive

 

17. A charge feels a force of 0.50 Newtons when it is 1 meter away from a Van de Graff Generator. The force will be ___ Newtons when the charge is moved 2 meters.

  1. 0.125
  2. 0.25
  3. 0.50
  4. 1.00
  5. 2.00

 

18. Two charges are 0.40 meters apart. One charge is 1.0 X 10-10 Coulombs. The other is 3.0 x 10-9 Coulombs. The force between these two charges is ___ Newtons.

  1. 1.69 X 10-8
  2. 6.75 X 10-9
  3. 0.050
  4. 1.5 X 10-7

 

19. If the both of the above charges are doubled, while the distance is doubled, by what factor will the force change?

  1. 1
  2. 2
  3. 4
  4. 1/2
  5. 1/4

 

20. Two charges separated by one meter exert a one N force on each other. If the charges are pushed to 1/4 meter separation, the force on each charge will be _________.

  1. 1 N
  2. 2 N
  3. 4 N
  4. 8 N
  5. 16 N

 

21. Two charges separated by one meter exert a one N force on each other. If the charges are pulled to 3 m separation distance, the force on each charge will be ________.

  1. 0.33 N
  2. 0.11 N
  3. 0 N
  4. 3 N
  5. 9 N

 

22. A charge of 0.30 Coulombs has a potential energy of 400 Joules has an electric potential (i.e., voltage) of ___ Volts.

  1. 1300
  2. 400
  3. 120
  4. 0.0075

 

 

 


Return to:

Unit 8 Review - Questions

Physics Reviews Home Page
Physics 163 Home Page
GBS Physics Home Page


[ Course Calendars | Makeup Labs | Physics Classroom | Multimedia Physics Studios | The Quiz Room | Packet Solutions (P163) | Extra Credit | Reviews | P173 Internet Problems | Chem-Phys Internet Problems | P163 Projects | The Refrigerator | Miscellaneous Help | E-Mail Physics Teachers | Conceptual Physics | Physics 163 | Physics 173 | Chem - Phys | AP Physics | GBS Physics Home Page | GBS Science Home Page ]


Comments and suggestions can be sent by e-mail to Tom Henderson.

This page last updated on February 14, 2000.