Measurement

Measurement is a technique that is required to measure and quantify various parameters of an object. Measurement is the essential metric to express any quantity of objects, things, and events that help us to compare that object with other similar objects. In our daily lives, we use measurement in various ways such are weighing vegetables at the mandi, measuring milk and petrol, etc.

In this article, we will learn about, Measurement Definition, Measurement Unit Table, Examples of measurement, and others in detail.

Measurement Definition

Measurement is the process of assigning a numerical value to a physical quantity or attribute of an object or phenomenon. Measurement helps us to compare, describe, and understand the world around us. For example, we can measure the length of a pencil, the mass of an apple, or the time it takes to run a race.

Measurement Unit Table

To measure different quantities, we need to use different units of measurement. A unit of measurement is a standardized quantity that can be used to express the magnitude of a physical quantity. For example, a meter is a unit of length, a kilogram is a unit of mass and a second is a unit of time.

There are different systems of units, such as the International System of Units (SI), the British Imperial System, and the US Customary System. The SI system is the most widely used and accepted system of units in the world. It consists of seven base units and several derived units. The table below shows some of the common units of measurement in the SI system and their symbols.

Quantity	Unit	Symbol
Length	meter	m
Mass	kilogram	Kg
Time	second	s
Temperature	kelvin	K
Electric current	ampere	A
Luminous intensity	candela	cd
Amount of substance	mole	mol

Types of Measurement

Basic types of measurement that we deal in several areas of mathematics and sciences are,

• Time
• Length
• Mass
• Volume
• Area
• Temperature

Measurement Conversion

Sometimes, we need to convert between different units of measurement to compare or calculate different quantities. For example, we may need to convert from metres to centimetres or from kilograms to pounds. To do this, we need to use conversion factors, which are ratios that relate one unit to another. For example, the conversion factor from metres to centimetres is 100, because 1 metre is equal to 100 centimetres. Similarly, the conversion factor from kilograms to pounds is 2.205, because 1 kilogram is equal to 2.205 pounds.

To convert from one unit to another, we need to multiply or divide by the appropriate conversion factor.

For example, to convert 5 metres to centimetres, we need to multiply by 100:

5 m × 100 = 500 cm

To convert 3 kilograms to pounds, we need to multiply by 2.205:

3 kg × 2.205 = 6.615 lb

To convert 10 seconds to milliseconds, we need to multiply by 1000:

10 s × 1000 = 10000 ms

To convert 25 degrees Celsius to kelvin, we need to add 273.15:

25 °C + 273.15 = 298.15 K

Measurement of Length

Length is the measure of how long or how far something is. The SI unit of length is the metre, which is defined as the distance travelled by light in a vacuum in 1/299792458 of a second. Some other common units of length are the kilometre (km), the centimetre (cm), the millimetre (mm), the micrometre (µm) and the nanometre (nm).

The table below shows some of the conversion factors between different units of length.

From	To	Conversion Factor
km	m	1000
m	cm	100
cm	mm	10
mm	µm	1000
µm	nm	1000

Measurement of Mass

Mass is the measure of how much matter an object contains. The SI unit of mass is the kilogram, which is defined as the mass of a platinum-iridium cylinder kept at the International Bureau of Weights and Measures in France. Some other common units of mass are the gram (g), the milligram (mg), the microgram (µg) and the nanogram (ng).

The table below shows some of the conversion factors between different units of mass.

From	To	Conversion Factor
kg	g	1000
g	mg	1000
mg	µg	1000
µg	ng	1000

Measurement of Time

Time is the measure of how long an event or process lasts. The SI unit of time is the second, which is defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom. Some other common units of time are the minute (min), the hour (h), the day (d) and the year (y).

The table below shows some of the conversion factors between different units of time.

From	To	Conversion Factor
hr	min	60
min	s	60
day	hrs	24
year	day	365

Measurement of Area

The table below shows some of the conversion factors between different units of Area.

From	To	Conversion Factor
m2	cm2	10000
m2	feet2	10.764
m2	yd2	1.196
feet2	yd2	9

Measurement of Volume

The table below shows some of the conversion factors between different units of Volume.

From	To	Conversion Factor
l	ml	1000
m3	l	1000
cm3	ml	1
m3	cm3	1000000

Measurement of Temperature

The table below shows some of the conversion factors between different units of temperature.

From	To	Formula
°C	°F	(0°C × 9/5) + 32 = 32°F
°C	K	0°C + 273.15 = 273.15K
°F	°C	(32°F − 32) × 5/9 = 0°C

Learn More,

• Fahrenheit to Celsius (°F to °C)

Measurement Instruments

Various Instruments that are used for measuring various physcial quantites are,

• Measurement Tape

• Clock

• Weighing Scale, etc.

Image of various measurement instruments is added below,

Application of Measurement

Measurement is essential for many fields of science, engineering, technology, and everyday life. Measurement allows us to observe, analyse and understand natural phenomena and human activities. Measurement also enables us to design, build, and operate machines, devices, and systems that improve our quality of life.

Some examples of the application of measurement are:

Astronomy: Measurement of the distance, size, mass, temperature, brightness, and motion of celestial bodies, such as stars, planets, moons, asteroids and comets.

Biology: Measurement of the structure, function, and behaviour of living organisms, such as cells, tissues, organs and systems.

Chemistry: Measurement of the composition, properties, and reactions of matter, such as atoms, molecules, elements and compounds.

Physics: Measurement of the fundamental forces and interactions of nature, such as gravity, electromagnetism, nuclear and quantum.

Engineering: Measurement of the performance, efficiency, and reliability of machines, devices, and systems, such as bridges, cars, planes, rockets and computers.

Medicine: Measurement of the health, diagnosis, and treatment of human and animal diseases, such as blood pressure, temperature, pulse, glucose and drugs.

Economics: Measurement of the production, distribution, and consumption of goods and services, such as GDP, inflation, unemployment and trade.

Education: Measurement of the knowledge, skills, and abilities of students, teachers, and schools, such as tests, grades and rankings.

Sports: Measurement of the speed, strength, endurance, and accuracy of athletes, teams, and games, such as time, distance, score and record.

Examples on Measurement

Here are some examples of how we can use the concept of measurement to solve problems or answer questions.

Example 1: How many litres of water can a cylindrical tank with a radius of 1.5 m and a height of 2 m hold?

Solution:

To find the volume of water that the tank can hold, we need to use the formula for the volume of a cylinder:

Given,

• r = 1.5 m
• h = 2 m

V = πr²h

Plugging in given values, we get:

V = π(1.5)²(2)

V ≈ 14.14 m³

To convert from cubic metres to litres, we need to multiply by 1000, since 1 cubic metre is equal to 1000 litres. Therefore, the tank can hold about 14140 litres of water.

Example 2: How long does it take for light to travel from the sun to the earth?

Solution:

To find the time that light takes to travel from the sun to the earth, we need to use the formula for the speed of light:

c = d​/t

Rearranging the formula, we get:

t = d/c​

Distance from the sun to the earth is about 149.6 million km, and the speed of light is about 300,000 km/s. Plugging in these values, we get:

t = 300000149600000​

t ≈ 498.67 s

To convert from seconds to minutes, we need to divide by 60, since 1 minute is equal to 60 seconds. Therefore, it takes about 8.31 minutes for light to travel from the sun to the earth.

Example 3: How much does a gold bar with a mass of 12.5 kg cost, if the price of gold is 50000 rupees per 10 grams?

Solution:

To find the cost of the gold bar, we need to multiply the mass of the gold bar by the price of gold per unit mass. However, before we do that, we need to convert the units of mass and price to the same unit.

Since the price of gold is given in rupees per 10 grams, we need to convert the mass of the gold bar and the price of gold to grams and rupees per gram, respectively.

To convert from kilograms to grams, we need to multiply by 1000, since 1 kilogram is equal to 1000 grams. To convert from rupees per 10 grams to rupees per gram, we need to divide by 10, since 10 grams is equal to 10 times 1 gram.

Therefore, we get:

m = 12.5 kg × 1000 = 12500 g

p = 50,000 rupees / 10 g ​= 5000 rupees per g

Now, we multiply mass of gold bar by price of gold per gram to get cost of gold bar:

c = m×p

c = 12500 g × 5000 rupees per g

c = 62500000 rupees

Therefore, the gold bar with a mass of 12.5 kg costs 62.5 million rupees.

Sample Questions on Measurement

Some Questions on Measurement are,

What is Difference between Accuracy and Precision in Measurement?

Accuracy is the degree of closeness of a measured value to the true value of the quantity. Precision is the degree of consistency or repeatability of a measured value. For example, if you measure the length of a table several times with a ruler, your measurements may be accurate but not precise, if they are close to the actual length but vary a lot. On the other hand, your measurements may be precise but not accurate, if they are consistent but far from the actual length.

What are Sources of Error in Measurement?

There are two main types of error in measurement:

• Systematic Error
• Random Error

Systematic error is the error that occurs due to a flaw in the instrument, method, or procedure of measurement. It causes the measured values to be either consistently higher or lower than the true value. Random error is the error that occurs due to unpredictable factors, such as human error, environmental conditions, or noise. It causes the measured values to fluctuate around the true value.

What are Significant Figures in Measurement?

Significant figures are the digits in a measured value that are known with certainty plus one digit that is uncertain or estimated. They indicate the precision of the measurement. For example, the value 3.14 has three significant figures, while the value 3.140 has four significant figures. The rules for determining the number of significant figures in a value are:

• All non-zero digits are significant. For example, 123 has three significant figures.
• Zeros between non-zero digits are significant. For example, 1003 has four significant figures.
• Zeros at the beginning of a value are not significant. They are only placeholders. For example, 0.0012 has two significant figures.
• Zeros at the end of a value are significant if there is a decimal point in the value. For example, 12.00 has four significant figures, while 1200 has two significant figures.

FAQs on Measurement

What Do you Mean by Measurement?

Measurement is the quantification of features of an object, that tells us about various properties of object and help usto compare various objects on various parameters.

What are 3 Types of Measurement?

The three types of measures are

• Descriptive
• Diagnostic
• Predictive

What are 7 Main Units of Measurement?

Seven basic SI Units are,

• Length – meter (m)

• Time – second (s)

• Mass – kilogram (kg)

• Electric Current – ampere (A)

• Temperature – kelvin (K)

• Amount of Substance – mole (mole)

• Luminous Intensity – candela (cd)

Is Light Year Unit of Time?

No, Light Year as the name suggest is not a unit of time but is a unit of Length. It is the distance travelled by light in an year and is equal to 9.4607 × 10¹² km.