Electric currents make magnetic fields

Answer Key - Grade 11 Science Worksheet - Challenge Me

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

1. 1.

   A coil 0.25 m long has 500 turns and carries 2 A. With μ₀ = 1.25663706127 × 10⁻⁶ N/A², what is the field inside, in mT, to 0.01, Ari?

   5.03 mT
2. 2.

   A coil 0.1 m long has 200 turns and carries 1.5 A. With μ₀ = 1.25663706127 × 10⁻⁶ N/A², what is the field inside, in mT, to 0.01, Bo?

   3.77 mT
3. 3.

   A coil 0.5 m long has 1000 turns and carries 0.8 A. With μ₀ = 1.25663706127 × 10⁻⁶ N/A², what is the field inside, in mT, to 0.01, Esme?

   2.01 mT
4. 4.

   A bar magnet's south pole is held near a coil's north end. What happens, Luz?

   • They attract
   • They repel
   • Nothing, since one is a coil
5. 5.

   Milo says moving three times farther from a long wire cuts its field to one-ninth. Agree or disagree?

   • Agree: fields fall as 1 ÷ r²
   • Disagree: it drops to one-third
   • Agree: like gravity, it's an inverse square
6. 6.

   Noah says a long wire's field 4 cm away is one-quarter of its field 2 cm away. Agree or disagree?

   • Agree: the field is gone by 4 cm
   • Agree: double the distance, one-quarter
   • Disagree: it is half
7. 7.

   Pia says a wire makes a magnetic field even with no current in it. Agree or disagree?

   • Agree: copper is magnetic
   • Disagree: it needs a current
   • Agree: wires are magnets
8. 8.

   A wire's current doubles, and the meter moves twice as far away. What happens to the field it reads, Ren?

   • It halves
   • It stays the same
   • It doubles
9. 9.

   A coil is rebuilt with twice the turns on twice the length, at the same current. What happens to its field, Tala?

   • It doubles
   • It stays the same
   • It is 4 times as strong
10. 10.

    A coil's current triples. What happens to the field inside it, Zee?

    • It is 9 times as strong
    • It triples
    • It stays the same