Magnetic field around a wire and inside a coil
Grade 11 Science Worksheet
Circle the best answer, or write your answer on the line.
A solenoid has 1200 turns over 0.4 m. What current gives a field of 9 mT inside, to 0.01 A, Esme? Use μ₀ = 4π × 10⁻⁷ T·m/A.
A solenoid has 300 turns over 0.15 m. What current gives a field of 2 mT inside, to 0.01 A, Jun? Use μ₀ = 4π × 10⁻⁷ T·m/A.
The current in a long wire doubles. What happens to the field 3 cm away, Kira?
- It doubles
- It stays the same
- It becomes 4 times as strong
A point moves from 2 cm to 6 cm away from a long wire. What happens to the field, Luz?
- It falls to a ninth
- It triples
- It falls to a third
The field 4 cm from a long wire is 50 μT. What is it 1 cm from the wire, Milo?
- 12.5 μT
- 800 μT
- 200 μT
A solenoid's turns per meter are doubled at the same current. What happens to the field inside, Noah?
- It doubles
- It halves
- It stays the same, since the current did not change
A solenoid is made twice as long by adding turns at the same spacing, at the same current. What happens to the field inside, Pia?
- It stays the same
- It doubles, since there are twice as many turns
- It halves, since it is twice as long
Solenoid A has 1000 turns over 0.5 m; solenoid B has 1000 turns over 0.25 m. Both carry 2 A. Which has the stronger field inside, Ren?
- They are equal, with 1000 turns each
- A, since it is longer
- B, with twice A's field
Read this first
Table (example data), field 2 cm from a long straight wire
Current 2 A, 20 μT; 4 A, 40 μT; 6 A, 60 μT; 8 A, 80 μT.
Using the table, how does the field change with the current, Tala?
- It grows as the current squared
- It grows in step with the current
- It stays the same for each current
Using the table, what would the field be at 4 cm for 8 A, Ari?
- 160 μT
- 40 μT
- 20 μT
