Magnetic force on a moving charge and on a wire

Answer Key - Grade 11 Science Worksheet

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

1. 1.

   A 3 μC bead moves at 400 m/s at 30° to a 0.5 T field. What force acts on it, to 0.01 mN, Bo?

   0.3 mN
2. 2.

   A 4 μC bead moves at 250 m/s at 60° to a 0.8 T field. What force acts on it, to 0.01 mN, Esme?

   0.69 mN
3. 3.

   A 2 μC bead moves at 600 m/s at 20° to a 0.25 T field. What force acts on it, to 0.01 mN, Jun?

   0.1 mN
4. 4.

   Field-line diagram (example data): a uniform field points into the page, drawn as × marks. In the diagram, which way is the force on the electron, Kira?

   • Down the page
   • Up the page
   • Into the page, along the field
5. 5.

   In the diagram, which way is the force on the electron, Milo?

   • To the right
   • Up the page, along its motion
   • To the left

6. Read this first

   Use this

   Table (example data), charged beads moving at right angles to a field, with columns bead, charge (μC), speed (m/s) and field (T): A, 2, 100, 0.5; B, 4, 100, 0.5; C, 2, 300, 0.5; D, 2, 100, 1.0.

7. 6.

   Using the table, which bead feels the largest force, Noah?

   • Bead C, at 0.3 mN
   • Bead D, in the strongest field
   • Bead B, with the most charge
8. 7.

   Using the table, how does bead D's force compare with bead A's, Pia?

   • D's force is 4 times A's
   • D's force is twice A's
   • D's force is half A's
9. 8.

   Using the table, which two beads feel equal forces, Ren?

   • Beads A and C, at 0.1 mN each
   • Beads C and D, at 0.3 mN each
   • Beads B and D, at 0.2 mN each
10. 9.

    A proton enters a uniform field at right angles to it. What happens to its speed, Tala?

    • It increases as the field pushes it
    • It decreases until it stops
    • It stays the same
11. 10.

    What path does a charge follow moving at right angles to a uniform field, by Ari's reading (OpenStax)?

    • A circle at a steady speed
    • A straight line that speeds up
    • A straight line along the field