1.0 Measurements And Their Errors

Question 1

SI unit for mass

Answer 1

Kilogram (Kg)

Question 2

SI unit for length

Answer 2

Meter (m)

Question 3

SI unit for time

Answer 3

Second (s)

Question 4

SI unit for amount of substance

Answer 4

Mole (mol)

Question 5

SI unit for temperature

Answer 5

Kelvin (K)

Question 6

SI unit for electrical current

Answer 6

Ampere (A)

Question 7

SI unit for light intensity

Answer 7

Candela (cd)

Question 8

Value of Terra (T)

Answer 8

×10¹²

Question 9

Value of Giga (G)

Answer 9

×10⁹

Question 10

Value of Mega (M)

Answer 10

×10⁶

Question 11

Value of Kilo (k)

Answer 11

×10³

Question 12

Value of Centi (c)

Answer 12

×10⁻²

Question 13

Value of Milli (m)

Answer 13

×10⁻³

Question 14

Value of Micro (μ)

Answer 14

×10⁻⁶

Question 15

Value of Nano (n)

Answer 15

×10⁻⁹

Question 16

Value of pico (p)

Answer 16

×10⁻¹²

Question 17

Value of femto (f)

Answer 17

×10⁻¹⁵

Question 18

J to eV conversion

Answer 18

1.6×10⁻¹⁹

Question 19

J to kW h conversion

Answer 19

2.778×10⁻⁷

Question 20

Define random errors

Answer 20

Unpredictable deviations in the result from the true value

Question 21

Define systematic errors

Answer 21

Constant deviations from true results due to flaws in experimental methods, instrument calibration, or environmental conditions.

Question 22

Define zero errors

Answer 22

A type of systematic error where a reading is given when the true reading should be zero

Question 23

Define precision

Answer 23

Degree of exactness or consistency in repeat readings

Question 24

Define repeatability

Answer 24

The ability to produce consistent results when repeated

Question 25

Define reproducibility

Answer 25

the ability to obtain the same results when with different equipment, different techniques or completed by another person

Question 26

Define resolution

Answer 26

The smallest change in a measured quantity that an instrument can detect or display

Question 27

Define accuracy

Answer 27

How close a result is to the true value

Question 28

Define uncertainty

Answer 28

The measure of how confident you can be in a measurement

Question 29

Absolute uncertainty

Answer 29

uncertainty given as a fixed quantity
e.g. 100 cm ± 1 cm

Question 30

Fractional uncertainty

Answer 30

uncertainty given as a fraction of the measurement

Question 31

Percentage uncertainty

Answer 31

uncertainty given as a percentage of the measurement

Question 32

Uncertainty in a reading

Answer 32

± half the smallest division

Question 33

Uncertainty in a measurement

Answer 33

at least ±1 smallest division

Question 34

Uncertainty in repeated data

Answer 34

± half the range

Question 35

The uncertainty in digital readings

Answer 35

± the last significant digit unless otherwise quoted

Question 36

Adding or subtracting data with uncertainties

Answer 36

add absolute uncertainties

Question 37

Multiplying or dividing data with uncertainties

Answer 37

add fractional or percentage uncertainties

Question 38

Raising data with uncertainties to a power

Answer 38

multiply the percentage uncertainty by the power

Question 39

How to measure uncertainty on graphs

Answer 39

Use error bars

Question 40

Directions of error bars

Answer 40

vertical - uncertainty in y
horizontal - uncertainty in x

Question 41

Error bar values

Answer 41

Shows the absolute uncertainty

Question 42

Best gradient in graph uncertainties

Answer 42

best line that passes as close to the points as possible

Question 43

Worst gradient in graph uncertainties

Answer 43

either the steepest possible or the shallowest possible line which fits within all the error bars

Question 44

Percentage uncertainty in the gradient

Answer 44

=(best - worst)÷best × 100

Question 45

Percentage uncertainty in the y-intercept

Answer 45

=(best - worst)÷best × 100

Question 46

Orders of magnitude

Answer 46

Scale of a value expressed as an order of 10

Question 47

Speed of sound in air

Answer 47

300m/s

Question 48

Atmospheric pressure

Answer 48

1×10⁵Pa