What is a Solenoid? Draw the pattern of the magnetic field lines around a current carrying solenoid. Mark on the pattern the region where the magnetic field is uniform.
Generated by claude-sonnet-4-6 · 2026-06-15 06:49 · grounding rag
Model Answer
Solenoid: A coil of many circular turns of insulated copper wire wrapped closely in the shape of a cylinder is called a solenoid.
Magnetic field pattern:
```
N S
|→ → → → → → → → → → → →|
|→ → → → → → → → → → → →| ← Uniform field (inside)
|→ → → → → → → → → → → →|
```
The field lines outside the solenoid are similar to those of a bar magnet. One end acts as the North pole and the other as the South pole.
Uniform field region: The magnetic field is uniform inside the solenoid, where the field lines are parallel and equally spaced straight lines.
Source: Chapter 12, Section 12.2.4
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Explanation
- Definition (1 mark): Always mention "many turns," "insulated copper wire," and "cylindrical shape."
- Diagram (1 mark): Draw a rectangular coil with arrows showing field lines — parallel inside, curved outside resembling a bar magnet. Label N and S poles.
- Uniform region (1 mark): Explicitly state it is inside the solenoid; parallel straight lines indicate uniform field. Examiners look for this specific statement.