Coulomb's law: the force between charges

Answer Key - Grade 11 Science Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.

1. 1.

   Two charged spheres push on each other with 90 mN. If the distance between their centers becomes 3 times as large, what is the force, Bo?

   10 mN
2. 2.

   Two charged spheres push on each other with 80 mN. If the distance between their centers becomes 4 times as large, what is the force, Esme?

   5 mN

3. Read this first

   Use this

   Field-line diagram (example data):

5. 3.

   In the diagram, do the two spheres attract or repel, Jun?

   • They repel
   • Neither, since the charges cancel
   • They attract
6. 4.

   In the diagram, how do the forces on the two spheres compare, Kira?

   Use the picture in question 3.

   • The + sphere feels more
   • They are equal and opposite
   • The − sphere feels more
7. 5.

   In the diagram, which way do the field lines run, Luz?

   Use the picture in question 3.

   • From the − sphere to the + sphere
   • From the + sphere to the − sphere
   • In circles around each sphere
8. 6.

   The distance between two charges doubles. What happens to the force, Noah?

   • It doubles
   • It halves
   • It drops to one-quarter
9. 7.

   The distance between two charges halves. What happens to the force, Pia?

   • It doubles
   • It halves
   • It is 4 times as big
10. 8.

    Two balloons both carry negative charge. Do they attract or repel, Ren?

    • Neither
    • Attract
    • Repel
11. 9.

    A positive sphere is near a negative sphere. Do they attract or repel, Tala?

    • Attract
    • Neither, since their charges cancel
    • Repel
12. 10.

    Two spheres both carry positive charge. Do they attract or repel, Zee?

    • Repel
    • Neither, since positives are neutral
    • Attract, since positive charges pull