Units and Prefixes R#1

Question 1

For each of the following units, state the quantity described and its meaning

Question 2

metre (m)

Answer 2

Length – Distance travelled

Question 3

kilogram (kg)

Answer 3

Mass – Quantity of matter

Question 4

second (s)

Answer 4

Time – Duration

Question 5

ampere (A)

Answer 5

Electric current – Flow of electric charge

Question 6

kelvin (K)

Answer 6

Temperature – Thermodynamic temperature

Question 7

mole (mol)

Answer 7

Amount of substance – Number of particles (6.022×10²³)

Question 8

candela (cd)

Answer 8

Luminous intensity – Brightness of light

Question 9

newton (N)

Answer 9

Force – 1 N = 1 kg·m/s²

Question 10

joule (J)

Answer 10

Energy, work – 1 J = 1 N·m

Question 11

watt (W)

Answer 11

Power – 1 W = 1 J/s

Question 12

coulomb (C)

Answer 12

Electric charge – 1 C = 1 A·s

Question 13

volt (V)

Answer 13

Electric potential – 1 V = 1 W/A

Question 14

ohm (Ω)

Answer 14

Electrical resistance – 1 Ω = 1 V/A

Question 15

farad (F)

Answer 15

Capacitance – 1 F = 1 C/V

Question 16

hertz (Hz)

Answer 16

Frequency – 1 Hz = 1 cycle per second

Question 17

pascal (Pa)

Answer 17

Pressure – 1 Pa = 1 N/m²

Question 18

tesla (T)

Answer 18

Magnetic field strength – 1 T = 1 Wb/m²

Question 19

weber (Wb)

Answer 19

Magnetic flux – 1 Wb = 1 V·s

Question 20

henry (H)

Answer 20

Inductance – 1 H = 1 Wb/A

Question 21

lumen (lm)

Answer 21

Luminous flux – 1 lm = 1 cd·sr

Question 22

degree Celsius (°C)

Answer 22

Temperature – °C = K - 273.15

Question 23

electronvolt (eV)

Answer 23

Energy – 1 eV = 1.602×10⁻¹⁹ J

Question 24

light year

Answer 24

Distance – Distance light travels in 1 year

Question 25

astronomical unit (AU)

Answer 25

Distance – Mean distance Earth–Sun ≈ 1.496×10¹¹ m

Question 26

degree (°)

Answer 26

Angle – 1° = π/180 radians

Question 27

litre (L or l)

Answer 27

Volume – 1 L = 1 dm³ = 10⁻³ m³

Question 28

atmosphere (atm)

Answer 28

Pressure – 1 atm ≈ 101,325 Pa

Question 29

ampere-hour (Ah)

Answer 29

Electric charge – 1 Ah = 3600 C

Question 30

tonne (t)

Answer 30

Mass – 1 tonne = 1000 kg

Question 31

year/day/hour/min

Answer 31

Time – Various non-SI time units

Question 32

For each of the following prefixes, state the magnitude described relative to the base unit (Ex: meter)

Question 33

giga (G)

Answer 33

Scale (multiplicative) – 1 G = 10⁹

Question 34

mega (M)

Answer 34

Scale (multiplicative) – 1 M = 10⁶

Question 35

kilo (k)

Answer 35

Scale (multiplicative) – 1 k = 10³

Question 36

centi (c)

Answer 36

Scale (multiplicative) – 1 c = 10⁻²

Question 37

milli (m)

Answer 37

Scale (multiplicative) – 1 m = 10⁻³

Question 38

micro (µ)

Answer 38

Scale (multiplicative) – 1 µ = 10⁻⁶

Question 39

nano (n)

Answer 39

Scale (multiplicative) – 1 n = 10⁻⁹