# Chapter 1 – Measurements and Experimentation

The following Topics and Sub-Topics are covered in this chapter and are available on MSVgo:

Introduction

You might have experienced measuring the length of your wall to finalize the size of the wardrobe. We constantly check the clock’s time to determine if we will make it on time to the destination. The topic Measurements and Experimentation is included in the Class 9 syllabus to understand better the different units and their relationship with the physical quantities like time, length, mass, temperature, etc.

Measurement is a process through which we can find the physical quantity’s magnitude compared to another well-known standard amount of similar nature. Measurement compromise of two parts namely,

• Unit is the standard quantity that is used to measure the given physical quantity.
• Numerical value or magnitude will help us determine how often the above-chosen unit is carried in the given item.

For example, if the weight of rice is 20 kgs, it implies that the unit to measure mass is kg, and this unit is carried 20 times in the mass of the rice.

From this, we conclude that,

Any Physical quantity= Numerical value X Unit

Units For Physical Quantities

The different units for physical quantities are classified into two types, namely,

• Fundamental units
It is the basic unit given to any physical quantity which does not have any relationship between any other fundamental unit nor can be changed—for example, units of physical quantities like mass, temperature, time, length.

• Derived Units
This type of unit has its derivation from the fundamental unit. For example, surface area or the volume of a surface is derived from the fundamental unit length.

#### International System Of Units

The International System of Units, also commonly called as S.I unit system. Countries like United States, United Kingdom, Canada, and many more have widely accepted in 1960.

There are seven fundamental and two complementary units included in the SI system. They are length, time, mass, luminous intensity, current, temperature, and quantity of the substance and Angle and solid angle.

We have tabulated below the International System of units for better readability.

 Physical quantity S.I. unit for Measurement Symbol Mass Kilogram Kg Length Meter m Time Second s Temperature Kelvin K Luminous intensity Candela cd Current Ampere A Quantity of substance mole mol Angle Radian rad Solid angle Steradian sr

The prefixes used for larger measurements in the International System of units are tabulated below.

 Prefix Symbol Meaning Deca da 101 Hecto h 102 Kilo k 103 Mega M 106 Giga G 109 Tera T 1012 Peta P 1015 Exa E 1018

#### Measurement Of Length

For the measurement of length, we can use a meter scale or vernier calipers.
A meter scale is a plastic, wooden, or metal scale with a maximum length of 1 meter or 100 cms. It is divided into 100 divisions, with each division or the least count 1mm or 0.1 cm.

We cannot use a meter scale for measurements to go up to 2 decimal places(0.01 cm).
Two scales, namely the main scale and the vernier scale, give us accuracy up to 0.01 cm.

Vernier calipers are used to measure any rod’s length, the diameter of the cylinder and sphere, etc.

A screw gauge ideally measures the wire or paper thickness. For a screw gauge, its pitch is the straight distance that the screw moves on the main scale while the circular scale completes one rotation.

#### Measurement Of Time

You might have experienced that your friend arrived late for the class on a particular day. We have always heard that time never waits for anyone. So the teacher starts with the lecture without waiting for latecomers. So we need to understand the measurement of time

We use Stopwatches in laboratories where shorter time intervals need to be measured. In contrast, you might have seen a wall clock at your homes to measure time. In this section, we will briefly discuss the working of a simple pendulum.

#### Working principle of Simple Pendulum

A simple pendulum consists of a heavy point-like object called bob that is suspended from fixed support using a string that can neither be extended nor has mass. Bob is an iron or brass ball suspended using a lightweight string from firm support.

Now when its bob is at rest at the position O. It is then released to pass horizontally from point A to point B passing through O.

It completes one oscillation when it moves from O to A, A to B, and then back to O.

Period of oscillation is the time needed by a simple pendulum to complete one oscillation, while the frequency of oscillation is the total number of oscillations completed in one second. The amplitude of oscillation is the maximum distance covered from the bob’s mean position on either of its side.

#### Conclusion

In this topic of Measurements and Experimentation, we have learned about the International System of units and their relations. Also, a meter scale is used for the measurement of length in daily life, while we prefer to use a simple pendulum for the measurement of time.

#### FAQs

1. What is a lunar month?
It is the time duration in which the moon completes one revolution around Earth.
2. How to find the least count of a screw gauge?
=
3. What is the relation between frequency and period of oscillation in a simple pendulum?
=
4. Give the expression to find the period for a simple pendulum.
=
T is the oscillation period, l is the string’s length, and g is the acceleration due to gravity.
5. What are the prefixes used for smaller measurements and experimentation?
 Prefix Symbol Meaning deci d 10-1 centi c 10-2 milli m 10-3 micro 10-6 nano n 10-9 pico p 10-12 femto f 10-15 atto a 10-18

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### High School Physics

• Alternating Current
• Atoms
• Communication Systems
• Current Electricity
• Dual nature of Radiation and Matter
• Electric Charges and Fields
• Electricity
• Electromagnetic Induction
• Electromagnetic Waves
• Electrons and Photons
• Electrostatic Potential and Capacitance
• Fluid Pressure
• Force and Acceleration
• Force And Laws Of Motion
• Gravitation
• Internal Energy
• Kinetic Theory
• Law of motion
• Light – Reflection And Refraction
• Magnetic Effects Of Electric Current
• Magnetism and Matter
• Management Of Natural Resources
• Mechanical properties of Fluids
• Mechanical properties of Solids
• Motion
• Motion in a plane
• Motion in a straight line
• Moving Charges and Magnetism
• Nuclear Energy
• Nuclei
• Oscillations
• Our Environment
• Paths of Heat
• Physical world
• Ray optics and optical instruments
• Semiconductor Devices
• Semiconductor Electronics: Materials, Devices and Simple Circuits
• Simple Machines
• Sound
• Sources Of Energy
• Specific and Latent Heats
• Spherical Mirrors
• Static Electricity
• Systems of Particles and Rotational motion
• Thermal properties of matter
• Thermodynamics
• Units and Measurement
• Vectors, Scalar Quantities and Elementary Calculus
• Wave Optics
• Waves
• Work, Power and Energy

### High School Chemistry

• Acids, Bases and Salts
• Alcohols, Phenols and Ethers
• Aldehydes, Ketones and Carboxylic Acids
• Aliphatic and Aromatic Hydrocarbons
• Alkyl and Aryl Halides
• Amines
• Analytical Chemistry
• Atomic Structure
• Atoms And Molecules
• Basic concepts of Chemistry
• Biomolecules
• Carbon And Its Compounds
• Carboxylic acids and Acid Derivatives
• Chemical Bonding and Molecular Structures
• Chemical Energetics
• Chemical Equilibria
• Chemical Kinetics
• Chemical Reactions And Equations
• Chemical Reactions and Their Mechanisms
• Chemistry in Everyday Life
• Chemistry of p-Block elements
• Chemistry of Transition and Inner Transition
• Classification of Elements
• Coordination Compounds
• Cyanide, Isocyanide, Nitro compounds and Amines
• Electrochemistry
• Electrolysis
• Elements, Compounds and Mixtures
• Environmental Chemistry
• Equilibrium
• Ethers and Carbonyl compounds
• Haloalkanes and Haloarenes
• Hydrocarbons
• Hydrogen
• Ideal solutions
• Introduction to Organic Chemistry
• Ionic equilibria
• Matter
• Matter Around Us
• Matter In Our Surroundings
• Metallurgy
• Metals And Non-Metals
• Mole Concept and Stoichiometry
• Natural Resources
• Organic Chemistry – Basic Principles
• Periodic Classification of Elements
• Physical and Chemical Changes
• Physical and Chemical Properties of Water
• Polymers
• Preparation, Properties and Uses of Compounds
• Principles and Processes of Isolation of Elements
• Redox Reactions
• Relative Molecular Mass and Mole
• States of Matter
• Structure Of The Atom
• Study of Compounds
• Study of Gas Laws
• Study of Representative Elements
• Surface Chemistry
• The d-block and f-block elements
• The Gaseous State
• The p-Block Elements
• The Periodic Table
• The s-Block Elements
• The Solid State
• Thermodynamics

### High School Biology

• Absorption and Movement of Water in Plants
• Anatomy of Flowering Plants
• Animal Kingdom
• Bacteria and Fungi-Friends and Foe
• Biodiversity and Conservation
• Biofertilizers
• Biological Classification
• Biomedical Engineering
• Biomolecules
• Biotechnology and its Applications
• Biotic Community
• Body Fluids and Circulation
• Breathing and Exchange of Gases
• Cell – Unit of Life
• Cell Cycle and Cell Division
• Cell Division and Structure of Chromosomes
• Cell Reproduction
• Cellular Respiration
• Chemical Coordination and Integration
• Circulation
• Control And Coordination
• Crop Improvement
• Digestion and Absorption
• Diversity In Living Organisms
• Ecosystem
• Environmental Issues
• Excretory Products and their Elimination
• Flowering Plants
• Genes and Chromosomes
• Health and Diseases
• Health and Its Significance
• Heredity And Evolution
• Heredity and Variation
• How Do Organisms Reproduce?
• Human Diseases
• Human Eye And Colourful World
• Human Health and Disease
• Human Population
• Human Reproduction
• Hygiene
• Improvement In Food Resources
• Integumentary System- Skin
• Kingdom Fungi
• Kingdom Monera
• Kingdom Protista
• Life Processes
• Locomotion and Movement
• Microbes in Human Welfare
• Mineral Nutrition
• Molecular Basis of Inheritance
• Morphology of Flowering Plants
• Neural Control And Coordination
• Nutrition in Human Beings
• Organism and Population
• Photosynthesis
• Photosynthesis in Higher Plants
• Plant Growth and Development
• Plant Kingdom
• Pollination and Fertilization
• Pollution; Sources and its effects
• Principles of Inheritance and Variation
• Reproduction and Development in Angiosperms
• Reproduction in Organisms
• Reproductive Health
• Respiration in Human Beings
• Respiration in Plants
• Respiratory System
• Sexual Reproduction in Flowering Plants
• Strategies for Enhancement in Food Production
• Structural Organisation in Animals
• Structural Organisation of the Cell
• The Endocrine System
• The Fundamental Unit Of Life
• The Living World
• The Nervous System and Sense Organs
• Tissues
• Transpiration
• Transport in Plants

### High School Math

• Algebra – Arithmatic Progressions
• Algebra – Complex Numbers and Quadratic Equations
• Algebra – Linear Inequalities
• Algebra – Pair of Linear Equations in Two Variables
• Algebra – Polynomials
• Algebra – Principle of Mathematical Induction
• Binomial Theorem
• Calculus – Applications of Derivatives
• Calculus – Applications of the Integrals
• Calculus – Continuity and Differentiability
• Calculus – Differential Equations
• Calculus – Integrals
• Geometry – Area
• Geometry – Circles
• Geometry – Conic Sections
• Geometry – Constructions
• Geometry – Introduction to Euclid’s Geometry
• Geometry – Three-dimensional Geometry
• Geometry – Lines and Angles
• Geometry – Straight Lines
• Geometry – Triangles
• Linear Programming
• Matrices and Determinants
• Mensuration – Areas
• Mensuration – Surface Areas and Volumes
• Number Systems
• Number Systems – Real Numbers
• Permutations and Combinations
• Probability
• Sequence and Series
• Sets and Functions
• Statistics
• Trignometry – Height and Distance
• Trignometry – Identities
• Trignometry – Introduction

### Middle School Science

• Acids, Bases And Salts
• Air and Its Constituents
• Basic Biology
• Body Movements
• Carbon and Its Compounds
• Cell – Structure And Functions
• Changes Around Us
• Chemical Effects Of Electric Current
• Coal And Petroleum
• Combustion And Flame
• Components Of Food
• Conservation Of Plants And Animals
• Crop Production And Management
• Electric Current And Its Effects
• Electricity And Circuits
• Elements and Compounds
• Fibre To Fabric
• Food production and management
• Force And Pressure
• Forests: Our Lifeline
• Friction
• Fun With Magnets
• Garbage In, Garbage Out
• Getting To Know Plants
• Health and Hygiene
• Heat
• Hydrogen
• Life Processes: Nutrition in Animals and Plants
• Materials: Metals And Non-Metals
• Matter and Its States
• Metals and Non-metals
• Micro Organisms: Friend And Foe
• Motion And Measurement Of Distances
• Motion And Time
• Nutrition In Animals
• Nutrition In Plants
• Organization in Living Things
• Our Environment
• Physical And Chemical Changes
• Pollution and conservation
• Pollution Of Air And Water
• Reaching The Age Of Adolescence
• Reproduction In Animals
• Reproduction In Plants
• Respiration In Organisms
• Rocks and Minerals
• Separation Of Substances
• Simple Machines
• Soil
• Some Natural Phenomena
• Sorting Materials Into Groups
• Sound
• Stars And The Solar System
• Structure of Atom
• Synthetic Fibers And Plastics
• The Living Organisms And Their Surroundings
• Transfer of Heat
• Transformation of Substances
• Transportation In Animals And Plants
• Universe
• Waste-water Story
• Water: A Precious Resource
• Weather, Climate And Adaptations Of Animals To Climate
• Winds, Storms And Cyclones

### Middle School Math

• Area and Its Boundary
• Boxes and Sketches
• Data Handling
• Fun With Numbers
• Heavy and Light
• How Many
• Long And Short
• Mapping
• Measurement
• Money
• Multiplication and Factors
• Multiply and Divide
• Numbers
• Parts and Wholes
• Pattern Recognition
• Patterns
• Play With Patterns
• Rupees And Paise
• Shapes And Angles
• Shapes And Designs
• Shapes and Space
• Similarity
• Smart Charts
• Squares
• Subtraction
• Tables And Shares
• Tenths and Hundredths
• Time