Module 2

Question 1

What are the seven base units?

What are they the units of?

Answer 1

Metre (m) (distance), kilogram (kg) (mass), second (s) (time), ampere (A) (electric current), Kelvin (K) (temperature), candela (cd) (luminosity) and mole (mol) (amount of substance)

Question 2

What are the units for radians?

Answer 2

ᶜ or rad

Question 3

Angle (radians) =

Answer 3

arc length (m) / radius (m)

Question 4

What are 90 ° and 180 ° in radians?

Answer 4

π/2 and π

Question 5

What are the prefixes and symbols for the powers of 10?

Answer 5

Power Name Symbol
15 Peta P
12 Tera T
9 Giga G
6 Mega M
3 Kilo k
-2 Centi c
-3 Mili m
-6 Micro µ
-9 Nano n
-12 Pico p
-15 femto f

Question 6

What are the two ways of estimating uncertainty?

Answer 6

Repeat it many times and make an estimate from the variation you get
Look at the process of measurement used, and inspect and test the instrument used (better, because you can the improve your experiment)

Question 7

What are the 7 properties of instruments?

Answer 7

Resolution, Sensitivity, Stability, Response time, Zero error, Noise, Calibration

Question 8

Define Resolution

Answer 8

The smallest detectable change in input

Question 9

Define Sensitivity

Answer 9

The ratio of output to input,

Question 10

Define Stability

Answer 10

Repeatability and Reproducibility

The extent to which repeated measurements give the same result, including gradual change with time (drift)

Question 11

Define Response time

Answer 11

The time interval between a change in input and the corresponding change in output

Question 12

Define Zero error

Answer 12

The output for 0 input

Question 13

Define Noise

Answer 13

Variations, which may be random, superimposed on a signal

Question 14

Define Calibration

Answer 14

Determining the relation between output and true input value, including linearity of the relationship