Beatty PURE PHYSICS PRACTICAL NOTES 6 Oct 2023

Beatty Secondary School O level Physics (6091) Science Department 1 PURE PHYSICS PRACTICAL NOTES 1. Reading and recording of raw data Precision of instruments The table below summarizes the precision of each instrument used in experiments. No Apparatus Smallest division Correct precision Example of recording Remarks 1 Ammeter (0 – 1 A) 0.02 A 0.01 A 0.24 A 0.31 A These instruments’ readings are recorded to half the smallest division. 2 Ammeter (0 – 1 A) 0.02 A 0.01 A 0.25 A 0.20 A 3 Voltmeter (0 – 3 V) 0.1 V 0.05 V 0.65 V 1.30 V 4 Voltmeter (0 – 5 V) 0.1 V 0.05 V 2.15 V 2.20 V 5 Laboratory thermometer (-10 to 110 ºC) 1 ºC 0.5 ºC 37.5 ºC 91.0 ºC 6 Half – metre rule 0.1 cm 0.1 cm 12.0 cm 12.1 cm These instruments’ readings are recorded to the smallest division. 7 Metre rule 0.1 cm 0.1 cm 88.3 cm 8 Protractor 1 º 1 º 36 º 45 º 9 Measuring cylinder (100 ml) 1 ml 1 ml or cm3 75 ml or cm3 10 Spring balance (0 – 1 N) 0.01 N 0.01 N 0.76 N 0.70 N 11 Spring balance (0 – 10 N) 0.1 N 0.1 N 3.7 N 3.6 N 12 Stop watch (digital) 0.01 s 0.01 s 36.54 s 20.72 s Reading to 2 d p unless otherwise stated. 13 Digital Micrometer screw gauge 0.01 mm 0.01 mm 2.00 mm 2.11 mm 14 Digital calipers 0.01 cm 0.01 cm 7.22 cm 7.89 cm 15 Electronic mass balance 0.01 g 0.01 g 121.00 g 2.45 g

Beatty Secondary School O level Physics (6091) Science Department 2 The method to obtain readings in some of the common instruments is discussed below. 1. Metre rule 2. Stop watch • Read to 2 d.p. unless otherwise stated (The time interval can be very short for some experiments and thus the question will specify to record timings to nearest second). • Record as 35.39 s • Read to 2 d.p. • Record as 1 min 35.39 s which is equivalent to 60 + 35.39 s = 95.39 s 3. Electronic mass balance • Reset the machine first (Press the “tare” button). • Once reading is stable, record reading accordingly in grams. 4. Vernier calipers • 2 d.p. (in cm) or 1 d.p (in mm) Note: Do not record timing as “3539” or “35 39” • Read to the smallest division. • Take note of the decimal place (d.p.) cm 1 d.p. (1.9 cm) mm whole number (19 mm) m 3 d.p. (0.019 m) 01: 35: 39

Beatty Secondary School O level Physics (6091) Science Department 3 5. Micrometer • 2 d.p. (in mm) 6. Thermometers (Laboratory) 7. Voltmeters & ammeters • Read up to half the smallest division for both. 2 d.p. Last digit: 0 or 5 2 d.p. Last digit: 0 to 9. • Re