precisions on instruments

Question 1

What is a scale reading?

Answer 1

reading off a single point on the scale and it has no physical meaning
*precision to take half the reading

Question 2

analog ammeter
1A range

Answer 2

1/2 SD: 0.01A
no of dp: 2
SD: 0.02A

Question 3

analog voltmeter
3V range

Answer 3

1/2 SD: 0.05V
no of dp: 1
SD: 0.1V

Question 4

thermometer

Answer 4

1/2 SD: 0.5°C
no of dp: 1
SD: 1°C

Question 5

measuring cylinder (100cm³)

Answer 5

no of dp: 1
smallest division: 1cm³
correct degree of precision: 0.5cm³

Question 6

metre rule + uncertainity

Answer 6

1/2 SD: 0.05cm
no of dp: 0/1/3
SD: 1mm/ 0.1CM /0.001m

0.2~0.5

Question 7

protractor

Answer 7

1/2 SD: 0.5°
no of dp: 1
SD: 1°

2~5

Question 8

Newton-meter
1N range
+ uncertainty

Answer 8

1/2 SD: 0.005°
no of dp: 2
SD: 0.01N

0.01 ~ 0.03 N

Question 9

micrometer

Answer 9

1/2 SD: 0.005mm
no of dp: 2
SD: 0.01mm

Question 10

vernier calipers

Answer 10

1/2 SD(single reading, no uncertainty): 0.05mm
no of dp: 1
SD: 0.5mm
2 readings: 0.1mm

Question 11

electronic mass balance

Answer 11

no of dp: 2
smallest division: 0.01g

Question 12

digital stopwatch + uncertainty

Answer 12

no of dp: 2
smallest division: 0.01s

0.2~0.5

Question 13

Why is the digital stopwatch is taken to 1dp?

Answer 13

Reduce random error as there is an uncertainty in the measurements due to human reaction time which is 03-0.5s.