Unit abbreviations

Question 1

seconds

Answer 1

s

Incorrect: sec

Question 2

liter per second

Answer 2

L/s

Question 3

millisecond

Answer 3

ms

Question 4

millilitre

Answer 4

mL

Question 5

ampere

Answer 5

A

Question 6

ampere • hour

Answer 6

Ah

Question 7

bit

Answer 7

b

Question 8

calorie

Answer 8

cal

Question 9

minutes

Answer 9

min

Question 10

lux

Answer 10

lx

Question 11

hour

Answer 11

h

Incorrect: hr, hrs, h., HR

Question 12

kelvin

Answer 12

K

Incorrect: °K, deg K

Question 13

meter

Answer 13

m

Question 14

watthour

Answer 14

Wh

Question 15

newton

Answer 15

N

Question 16

ounce

Answer 16

oz

Question 17

pound-force

Answer 17

lbf

Question 18

mile

Answer 18

mi

Question 19

Are the SI unit short form abbreviations?

Answer 19

The short forms for SI units (such as mm for millimeter) are symbols , not abbreviations

Question 20

Do you end SI symbols with periods?

Answer 20

SI symbols never end with a period unless they are the last word in a sentence

Question 21

Do you use plural form when referring to multiple things?

Answer 21

Symbols always are written in the singular form (even when more than one is meant).

Example of wrong form: 36 kgs.

However, you do pluralize the written-out unit names: 36 kilograms.

Question 22

Do you write the unit name right after the number?

Answer 22

SI symbols should be preceded by digits and a space must separate the digits from the symbol .

• RIGHT: It was 300 mm wide. The millimeter width was given.
• WRONG: It was 300mm wide. The mm width was given.

Question 23

How do you write a quotient?

Answer 23

The symbol for a compound unit that is a quotient of two units is indicated by a solidus or by a negative exponent.

• RIGHT: km/h or km·h -1 (for kilometers per hour)
• WRONG: kmph or kph (do not use p as a symbol for “per”.)
• BUT: It is correct to say or write “kilometers per hour”.

Question 24

Celsius

Answer 24

°C

Incorrect: C, deg C, ° C

Question 25

microgram

Answer 25

μg

Question 26

How much is the prefix “deca”?

Answer 26

ten, or 10^0.

Note that in the US, the spelling is usually “deka”.

Question 27

How much is the prefix “hecto”?

Answer 27

100

10^2

Question 28

How much is the prefix “peta”?

Answer 28

1 quadrillion, or 10^15.

Comes after tera (10^12).

Question 29

How much is the prefix “pico”?

Answer 29

10^-12

Comes after nano.

Question 30

How should kilometre be pronounced?

Answer 30

The word kilometre should be pronounced ki-lo-me-te, not kil-lom-e-ter.