Safety & Hierarchy
A physics laboratory requires safety awareness and equipment competence.
The Safety hierarchy ranks protections from most to least effective:
| Level | Control Type | Example |
|---|---|---|
| 1 | Eliminate | Remove the hazard |
| 2 | Substitute | Safer alternative |
| 3 | Engineering | Fume hoods, shields |
| 4 | Administrative | Training, procedures |
| 5 | PPE | Goggles, gloves |
Tip: Estimate expected results before starting. Wildly different numbers mean setup errors, not new physics.
Common pitfall: Meter placement. An ammeter in parallel acts as a short circuit. A voltmeter in series blocks current. Know internal resistances to avoid blowing fuses.
Instruments & Notebooks
Precision depends on correct instrument reading rules:
| Instrument | Measures | Resolution |
|---|---|---|
| Vernier caliper | Length | mm |
| Micrometer | Thickness | mm |
| Digital balance | Mass | g |
| Multimeter | , , | Varies |
| Oscilloscope | Signals | s |
Reading rules:
- Analogue: Read to half the smallest division.
- Digital: The last displayed digit is the resolution.
- Vernier scales: The aligned mark gives the extra digit.
Lab notebook rules: Record all data directly in pen, never loose paper. Cross out mistakes—do not erase. Always include dates, setup sketches, and units.