Living Creatures : Exploring Their Characteristics - Class 6 Science - New St. Mery English School

Have you ever wondered how we know that a plant, an animal, or even a tiny insect is a living thing? The world around us is full of both living and non-living things, but living creatures have some special features that make them different. In this chapter, we will explore those unique characteristics that all living organisms share.

Living things grow, breathe, need food, move, respond to changes around them, reproduce, and remove waste from their bodies. These processes are called life processes, and they help living organisms survive on Earth. From huge elephants to tiny ants and green plants, every living being shows these characteristics in one way or another.

Understanding these features helps us learn more about nature and the amazing diversity of life around us. Let’s begin our journey into the fascinating world of living creatures and discover what truly makes something “alive.” 🌱 

Living Creatures : Exploring Their Characteristics - Class 6 Science - New St. Mery English School

What are living things?

Ans:- Things which have lives are called living things.

Ex:- human, plants, animals, birds etc

What are Non-living things?

Ans:- Things which have no lives are called Non-Living things.

Ex:- river, mountain, buildings etc

Write some common features between living thing and non-living thing.

Ans:-  Some common features between living thing and non-living thing are

1- Both Living and Non-living thing possess mass, shape and occupy space.

2- Both Living and Non-living thing  made up of basic structural unit. In the case of Living thing, Cell is the basic structural unit. and Molecule is the basic structural unit of Non-living thing.

Cellular Organisation

What are Cellular Organisms?

Ans:- Those organisms that are made of cells are called Cellular Organisms.

Ex:- animals, plants, amoeba etc

How many types of cellular organisms?

Ans:- There are two types of cellular organisms.

1- Unicellular organisms

2- Multicellular organisms

What are Unicellular organisms?

Ans:- Those organisms that are made up of only a single cell are called Unicellular organisms.

Ex:- amoeba, paramecium, euglena, chlamydomonas, bacteria

What are Multicellular organisms?

Ans:- Those organisms that are made up of millions of cells are called Multicellular organisms.

Ex:- plants, animals and human beings etc

Eating and Feeding

What is Nutrition?

Ans:- The process of taking food in living organisms is called Nutrition.

How many types of living organisms on the basis of Nutrition?

Ans:- There are two types of living organisms on the basis of Nutrition.

1- Autotrophic

2- Heterotrophic

What are Autotrophic?

Ans:- Those living organisms that prepare their own food themselves are Autotrophic.

Ex:- Plants are autotrophic because they synthesize their food themselves in the presence of sunlight and using raw material like carbon dioxide and water.

What are Heterotrophic?

Ans:- Those living organisms that get their food from plants and other animals are Heterotrophic

Ex:- Human beings, animals, birds etc

Respiration

What is breathing?

Ans:- The act of taking in air is called breathing. During breathing, the organisms take in oxygen present in the air. This oxygen is used to break down complex food substances into carbon dioxide and water. During this process, energy is released.

Food + Oxygen → Carbon dioxide + Water + Energy

What is Respiration?

Ans:- The release of energy from food is called respiration. Respiration helps living things obtain this energy. Living things need energy to grow, to move and to fight diseases.

Describe the different organs present in different organisms to breathe.

Ans:- Humans breathe in air through the nostrils into the lungs. Animals living in water, such as fish, use their gills to extract dissolved oxygen from water. Some animals, which do not have gills or lungs, breathe in other ways. Earthworms breathe through their body surface while insects breathe through holes in their bodies called spiracles. Plants breathe through special openings present in their leaves called stomata.

What is Growth?

Ans:- Growth is the increase in size, height, weight, or mass of a living organism over time. All living things show growth. 

Ex:- A baby grows into child, A seedling grows into a tree, A chicken grows into a cock, etc

Is growth reversible or irreversible?

Ans:- Growth is reversible because once a living thing has grown, it can not become small again.

Movement

Why is movement necessary in living organisms?

Ans:- Movement is necessary in living organisms because they move from one place to another in search of food, seeking protection from enemies and natural hazards that help them to survive on earth.

What is Locomotion?

Ans:- Locomotion is the movement of an organism from one place to another.

Ex:- Human walks, Birds fly, Fish swim, etc.

Excretion

What is Excretion?

Ans:- Elimination of wastes from the body of living organisms is called excretion. Animals excrete wastes from their bodies in the form of urine, stool and sweat. plants excrete gum and latex. plants like rubber, oak, and banyan trees excrete latex.

Response to stimuli

What is stimulus?

Ans:- Any change that produces an immediate action or response in an organism is called stimulus.

What is response?

Ans:- A response is the immediate action taken by an organism to adjust itself  according to the change.

Write about different kinds of stimulus that is responded by living organisms.

Ans:- All living organisms respond to different kinds of stimuli like touch, chemicals, heat, light and smell.

A turtle withdraws into its shell when sensing danger.

A bacterium swims away from concentration of harmful substances.

If you heat an animal, it will try to attack back or run away.

Sunflower shows response to stimuli mainly through movement toward light.

The touch-me-not plant shows a very clear response to touch, which is a type of stimulus. When the leaves of the touch-me-not plant are touched, shaken, or even exposed to strong wind, The leaflets quickly fold inward and the leaf droops down.

Reproduction

What is Reproduction?

Ans:- Reproduction is the process by which living organisms produce new organisms of their own kind.

Adaptation

What is adaptation?

Ans:- Living organism develops certain characteristics which help them to live and survive in their environment. This is called adaptation. Adaptation is the process by which a living organism learns to survive and reproduce in its environment.

Write some adaptations shown by different animals

Ans:- A polar bear has a thick fur to helps it keep warm in the polar regions.

A hawk has a sharp and hooked beak for tearing its prey.

A woodpecker uses its long and pointed beak to drill into the bark of trees to find insects.

A dog adapts to warm weather by shedding its hair.

Insect Eating plants

What are insectivorous plants?

Ans:- Insectivorous plants are special plants that trap and digest insects to get nutrients, especially nitrogen, because they usually grow in nutrient-poor soil.

Key points:

• They are green plants and can make their own food by photosynthesis 🌱

• They catch insects using modified leaves

• Insects provide extra nutrients, not energy

Common examples:

• Pitcher Plant – traps insects in a pitcher-shaped leaf

• Venus Flytrap – snaps shut when an insect touches it

• Sundew – has sticky hairs that trap insects

Life Span

What is Life Span?

Ans:- Life span is the total length of time for which a living organism lives, from birth to natural death.

Examples:

• Human – about 70–80 years

• Dog – about 10–15 years

• Butterfly – a few weeks

• Neem tree – hundreds of years

In short:-

Life span = Birth → Growth → Old age (maturity ) → Death

Write the organisms which show the characteristics of both living and non-living things.

Ans:- Viruses are the organisms which show the characteristics of both living and non-living things. Viruses need living cells to grow and reproduce. Most viruses can not survive for long if they are not inside a living thing. When viruses get inside living bodies, they multiply and make people sick. 

  

 

Air - Class 2 Science - New St. Mery English School

Air is all around us, even though we cannot see it. We need air to breathe and stay alive. Every plant, animal, and human being needs air. Air helps us to speak, fly kites, dry clothes, and move boats and windmills.

Air is made of different gases, and it gives us oxygen to breathe. Without air, life on Earth would not be possible. Even fire needs air to burn.

In this chapter, we will learn what air is, where we find it, and why it is so important for us. Let us explore the wonderful world of air and see how it helps us every day! 🌈 

Air - Class 2 Science - New St. Mery English School

What is Air?

Ans:- Air is a mixture of gases that surrounds the Earth and is necessary for all living things to breathe.

Features of Air

Air is all around us.
We cannot see air, but we can feel it.
Air helps us to breathe.
Plants, animals, and humans need air to live.
Air helps birds fly and helps fire burn.

What does air contain?

Ans:- Air contains many gases, water vapour, smoke, dust particles and germs

Write three properties of air.

Ans:- The three properties of air are

1- Air supports burning.

2- Air occupies space.

3- Air has weight.

How many types of air according to movement?

Ans:- There are four types of air according to movement.

1- Still air

2- breeze

3- wind

4- storm

What is still air?

Ans:- When air does not move, It is called still air.

What is breeze?

Ans:- gentle moving air is called breeze. It is soft and pleasant.

What is wind?

Ans:- Fast moving air is called wind.

What is storm?

Ans:- Very fast and strong air along with rain and thunder is called storm. It is very harmful.

Writ four uses of air?

The four uses of air are

1- We need air to breathe.

2- We need air for burning fire.

3- We need air to inflate balloons and tyres.

4- We need air for drying clothes.

What does make the air dirty?

Ans:- Smoke, germs and dust make the air dirty.

Why do we need fresh and clean air?

Ans:- If we breathe dirty air, We fall sick. To stay healthy, We need fresh and clean air.

How can we keep air clean?

Ans:- We can keep air clean by following ways

1- We should plant more and more trees.

2- Factories should be built away from the city to reduce the smoke in the air.

3- We should use public transport like bus, trains. It helps to reduce air polution.

electric current and Its Effects - Class 7 Science - New St. Mery English School

Electricity plays an important role in our daily life. From lighting our homes to running fans, televisions, and mobile phones, everything depends on the flow of electricity. This flow of electric charge is called electric current. Without electric current, most of the modern machines we use today would not work.

In this chapter, Electric Current, students will learn what electric current is, how it flows through a circuit, and how it helps electrical devices to function. We will also study electric cells, batteries, switches, and conductors, which are necessary for the flow of electric current. Understanding this topic will help students know how electricity is produced, controlled, and used safely in our everyday life.

This lesson builds a strong foundation for learning more about electricity in higher classes and helps students become more aware of energy and its uses.

electric current and Its Effects - Class 7 Science - New St. Mery English School

Electric current is the flow of electric charges (usually electrons) through a conductor like a wire.

👉 Electric current is the movement of electricity from one place to another.

It is represented by 'I'

Example:

When you switch on a bulb, electric current flows through the wire to the bulb and makes it glow 💡.

Unit:

Electric current is measured in ampere (A).

Electric Current = Electric Charge / time

I = Q / t

Where:

I = Electric current (in ampere, A)

Q = Electric charge (in coulomb, C)

t = Time (in seconds, s)

The SI unit of electric current is Ampere because electric current cannot be measured directly, but its magnetic effect can be measured very accurately.

When electric current flows through a wire, it produces a magnetic field around it. Scientists found that this magnetic effect can be measured very precisely. So, they decided to define electric current using this effect.

Scientific idea:

One ampere is the amount of current which, when flowing through two parallel wires, produces a fixed magnetic force between them.

In simple words:

👉 Ampere is used as the SI unit because it allows electric current to be measured accurately and reliably.

Who was André-Marie Ampère?

André-Marie Ampère (1775–1836) was a French physicist and mathematician.

He is known as the “Father of Electrodynamics.”

Why is the unit named Ampere?

He discovered the relationship between electricity and magnetism.

His work showed that electric current produces magnetic effects, which is the basis for motors, generators, and many electrical devices.

To honor his contribution: 👉 The SI unit of electric current was named “Ampere (A)” after him.

Numerical 

Q1. If 10 coulomb of charge flows in 5 seconds, find the electric current.

Q2. A charge of 30 C flows through a wire in 10 s. Find the current.

Electric charge 

Electric Charge is a property of matter that causes it to experience electrical force.

In simple words:

👉 Electric charge is the reason why objects attract or repel each other electrically.

It is represented by 'Q'

Types of electric charge

There are two types:

Positive charge

Negative charge

Example:

When you rub a balloon on your hair, it gets electric charge and can stick to a wall 🎈. This happens because of electric charge.

The SI unit of electric charge is Coulomb.

Symbol - C

👉 1 coulomb (C) is the amount of charge that flows when 1 ampere of current flows for 1 second.

Electric Charge = Electric Current × Time 

Who was Charles-Augustin de Coulomb?

Charles-Augustin de Coulomb (1736–1806) was a French physicist.

He studied the forces between electric charges and magnetic poles.

Why is the unit named Coulomb?

He discovered a law called Coulomb’s Law, which explains: 👉 How electric charges attract or repel each other.

To honor his work, the SI unit of electric charge was named “Coulomb (C)” after him.

Numerical 

Q1. How much charge flows if a current of 5 A flows for 4 seconds?

Q2. A current of 2 A flows for 15 seconds. Find the charge.

How many types of substances on the basis of electric current 

Ans:- There are two types of substances on the basis of electric current.

1- Conductors 

2- Insulators 

What are Conductors?

Ans:- Substances which allow electric current to flow through them are called conductors.

Ex:- Metals like aluminium, iron, copper, etc, alkali solutions, acid solutions, etc. are good conductors of electricity

What are Insulators?

Substances which do not allow electric current to flow through them are called insulators.

Ex:- Wood, plastic, paper, rubber, air, etc.

Electric Circuit 

What is electric Circuit?

Ans:- The path along which electric current flows is called electric circuit. An electric circuit consists of a number of components like cell or battery, connecting wires, switch, bulb etc. These components are called the elements of an electric circuit. The elements of a circuit are connected between the two terminal of a cell that is( +ve and -ve ). The current starts from the positive terminal of a cell, passes through the various conducting elements connected to it and ends at the negative terminal of the cell

How many types of electric Circuit?

There are two types of electric Circuit 

1- Closed electric Circuit 

2- Open electric Circuit 

What is Closed electric Circuit?

Ans- The circuit in which the various components are connected between the cells without any break is called a closed electric circuit.

Electric current flows through a closed circuit.

What is Open electric Circuit?

Ans- The circuit in which the various components connected between the cells have a break at some point is called an open electric circuit.

No current flows through an open circuit.

Elements of Circuit 

Cell  - : Cell is the source of electric current. It has two terminals, one positive and the other negative. The most commonly used cell in the laboratory is the dry cell.

Battery - the combination of two or more cells to produce electric current is called battery. In a battery the individual cells are connected in series or parallel.

How many types of battery? 

There are two types of battery. 

1- battery with cells in series 

2- battery with cells in parallel 

Battery with cells in series

In this kind of battery, the individual cells are connected in such a way that positive terminal of one cell is connected to the negative terminal of the other cell.

Battery with cells in parallel 

In this kind of battery, the individual cells are connected in such a way that their positive terminals are connected to each other and the negative terminals connected to each other with one free positive and one free negative terminal.

Switch 

Switch is a simple device used to turn an electric circuit ON or OFF.

Switch is another important element of the

circuit. It helps us to close or open the circuit. When the switch is in 'ON' position, the current flows through the circuit. The circuit is now said to be closed. On the other hand, when the switch is in 'OFF' position, no current flows through the circuit. The circuit is now said to be open.

A switch does not have terminals and can be connected anywhere in the circuit.

Bulb

An electric bulb is a device that produces light when electric current passes through it.

Inside the bulb there is a very thin wire called a filament. When electricity flows through the filament, it becomes very hot and glows, giving us light.

The bulb has a thin wire, called the filament that glows when current passes through it. If the filament is broken, the bulb will not glow. It is then said to be fused. A fan uses electric current to rotate to blow air.

Connecting wire

It is used to connect various components in an electric circuit. It is made of copper or aluminium coated with insulating material like plastic.

Voltmeter 

Ammeter 

Why are symbols for some electric components used instead of components?

Symbols for electric components are used in a circuit diagram instead of drawing the real components because:

1. They make diagrams simple and clear

Real components are big and complicated to draw. Symbols are small and easy, so the diagram looks neat.

2. They save time and space

Using symbols is much faster than drawing actual bulbs, cells, wires, etc.

3. They are understood all over the world

Electric symbols are standard. Scientists, engineers, teachers, and students everywhere understand the same symbols.

4. They help us understand the circuit easily

Symbols show how components are connected, so we can quickly follow the flow of electric current.

5. They avoid confusion

Real drawings may look different, but symbols are fixed, so there is no misunderstanding.

Some commonly used diagram of components are shown below 

Volt

Volt is the force that pushes electric charges. Volt is the unit that tells us how strong the push of electricity is. 

Volt (V) is the unit of electric potential difference. 

One volt is the potential difference when 1 joule of energy is used to move 1 coulomb of charge.

1 volt = 1 Joule / 1 Coulomb 

📌 Example

A 1.5 V battery gives small push (used in toys)

A 12 V battery gives stronger push (used in vehicles)

220 V is used in homes

Nature's Treasures - Class 6 Science - New St. Mery English School

Nature has gifted us many wonderful things that help us to live and grow. These valuable gifts are called Nature’s Treasures. Air, water, soil, sunlight, forests, animals, minerals, and fuels are all important natural resources that support life on Earth. Without these treasures, survival would not be possible.

In this chapter, students of Class 6 – New St. Mery English School will learn about different types of natural resources, how they are used in our daily life, and why we must protect them. We will also understand the difference between renewable and non-renewable resources and how careless use can harm our environment.

Let us explore Nature’s Treasures and learn how to use them wisely to keep our planet healthy for future generations 🌍 

Nature's Treasures - Class 6 Science - New St. Mery English School

What are Natural Resources?

Ans:- The sources which are obtained from nature are called Natural Resources. 

How many types of Natural Resources?

Ans:- There are two types of Natural Resources.

1- Renewable Resources

2- Non-renewable Resources

What are Renewable Resources?

Ans:- Renewable Resources are natural resources that can be replaced naturally in a short period of time. They do not get exhausted easily if used wisely.

Ex:- Sunlight, wind, water, air, plants and forest etc

What are Non-Renewable Resources?

Ans:- Non-Renewable Resources are natural resources that cannot be replaced quickly once they are used up. They take millions of years to form, so if they finish, nature cannot make them again in a short time.

Ex:- coal, petroleum, natural gas, minerals etc

Air

What is Air?

Ans:- Air is a mixture of gases that surrounds the Earth and is essential for all living beings. It is invisible but can feel it when it blows.

What is Air Made Of?

Ans:- Air is the mixture of gases. It contains 78.084% of Nitrogen, 20.946% of Oxygen, 0.934% of argon, 0.033% of Carbon dioxide, many other gases like hydrogen, helium, neon, methane etc. It also contains water vapour, dust and smoke particles.

Write about the history of composition of air.

Ans:- In earlier times, it was believed that air was an element. In 1674, Mayow showed that air consisted of one active and another inactive constituent. In 1775, Lavoisier proved that air is a mixture of nitrogen and oxygen gases. Later on, It was proved that air is a mixture of several gases. Near the surface of earth, air contains mainly two gases- nitrogen and oxygen. 

Write an experiment that shows the presence of carbon dioxide in exhale air.

Experiment to Show the Presence of Carbon Dioxide in Exhaled Air (Using Lime Water)

Aim

To show that exhaled air contains carbon dioxide (CO₂).

Materials Required

A test tube or glass

Fresh lime water

A straw

Procedure

Take a test tube or glass and fill it halfway with fresh lime water.

Put a clean straw into the lime water.

Now blow gently through the straw into the lime water for a few seconds.

Observe the change in the lime water.

Observation

The clear lime water turns milky.

Conclusion

The milkiness of lime water shows the presence of carbon dioxide in exhaled air.

Explanation

When carbon dioxide from our breath passes into lime water, it reacts with calcium hydroxide in lime water to form calcium carbonate, which is white and makes the solution milky.

Result

This proves that carbon dioxide is present in exhaled air

Write an experiment that Show That an Empty Glass Is Filled with Air

Experiment: To Show That an Empty Glass Is Filled with Air

Aim:

To show that an empty glass is actually filled with air.

Materials Required:

A glass

A bowl or bucket filled with water

A tissue paper (optional, for better understanding)

Procedure:

Take a dry glass and push a small piece of tissue paper firmly into the bottom of the glass.

Hold the glass upside down (mouth facing downward).

Slowly lower the inverted glass straight into the bowl of water.

Do not tilt the glass while lowering it into the water.

Take the glass out of the water and observe the tissue paper.

Observation:

The tissue paper inside the glass remains dry even after the glass is immersed in water.

Conclusion:

The tissue paper does not get wet because the glass was already filled with air. The air inside the glass occupies space and prevents water from entering the glass.

Hence, this experiment proves that an empty glass is actually filled with air.

Result:

Air occupies space.

Write an experiment to Show That air is present in water in dissolved form 

Experiment: To Show That Air Is Present in Water in Dissolved Form

Aim:

To show that air is present in water in dissolved form.

Materials Required:

A beaker or glass

Water

A burner or stove (adult supervision required)

A tripod stand and wire gauze (optional)

Procedure:

Take some water in a beaker or glass.

Heat the water slowly on a burner or stove.

Observe the inner sides and bottom of the beaker carefully while heating.

Continue heating until the water is about to boil.

Observation:

Before the water starts boiling, tiny bubbles appear on the sides and bottom of the beaker and rise to the surface.

Explanation:

These tiny bubbles are not steam. They are bubbles of air that were dissolved in water. When water is heated, the dissolved air escapes in the form of bubbles.

Conclusion:

This experiment shows that air is present in water in dissolved form.

Result:

Water contains dissolved air.

Write an experiment to show that soil contains air.

Experiment: To Show That Soil Contains Air

Aim:

To show that soil contains air.

Materials Required:

A beaker or glass

Dry soil

Water

Procedure:

Take some dry soil in a beaker or transparent glass.

Slowly pour water into the beaker containing soil.

Observe the soil carefully.

Observation:

Small air bubbles are seen coming out of the soil and rising to the surface of the water.

Explanation:

The air present in the spaces between soil particles escapes in the form of bubbles when water is poured into the soil.

Conclusion:

This experiment proves that soil contains air.

Result:

Soil has air in the spaces between its particles.

Write an experiment to Show That Oxygen in Air Is Needed for Combustion

Aim

To show that oxygen in air is necessary for burning (combustion).

Materials Required

A small candle

A glass jar or tumbler

A plate

Some water

Matchstick

Procedure

Fix the candle on the plate using some melted wax.

Pour a little water into the plate around the candle.

Light the candle with a matchstick.

Now cover the burning candle with a glass jar.

Observe what happens.

Observation

The candle flame burns for a few seconds and then goes out.

Conclusion

The flame goes out because the oxygen inside the jar is used up.

This shows that oxygen is needed for combustion.

Explanation

Air contains oxygen which supports burning.

When the candle is covered with a jar, no fresh air can enter.

The oxygen inside the jar gets used up, so the candle stops burning.

Result

This proves that oxygen in air is necessary for combustion.

How is the balance of oxygen and carbon dioxide maintained in the air?

The balance of oxygen and carbon dioxide in the air is maintained by the continuous cycle of photosynthesis (plants use CO2, release O2) and respiration.

Oxygen is used by living organisms for respiration. During respiration, oxygen breaks down the food to give energy. During this process, carbon dioxide and water vapour are produced and released. Carbon dioxide, along with water, is used by green plants in the presence of sunlight to make their own food. This process is called photosynthesis. In nature, the balance of oxygen and carbon dioxide is thus maintained.

Uses of Air

1. Air is required by human beings for respiration.

2. Air supports burning. No substance can burn in the absence of oxygen. Oxygen is necessary for the burning of all substances like wood, coal, paper, etc.

3. While winnowing, the breeze or the moving air helps to blow away the lighter husk thus helping to separate it from the grains.

4. Air helps in drying agricultural products such as grains, pulses, dry fruits, etc. Things dry faster in the wind.

5. Air helps in the pollination of flowers. Air helps in the dispersal of seeds and fruits.

6. Air helps in the movement of sailboats, gliders, parachutes and aircraft.

7. Air is filled in the tube of a bicycle tyre to inflate it. This makes it easier for the wheels of the bicycle to go faster.

8. Compressed air is used in the brake system for stopping trains.

9. Compressed air is used in machines for digging, mining and breaking stones.

10. Air makes the windmills move windmill are used to draw water from tubewells and run flour mills. Along the coast, windmills are also used to generate electricity

Water

Water is essential for the survival of all living things. About three-fourths of the Earth's surface is covered with water. Water is also present underground and in glaciers in the form of ice and it exists in the air in the form of water vapour. Most of the water on Earth (about 97%) is in the seas and oceans and is saltywhich is unsuitable for drinking and irrigation. Only 3% of water is available as fresh water. Only 0.01% of fresh water is easily available to us as surface water.

Importance of Water

Water is essential for life. While a person can survive without food for several weeks, they cannot last more than a few days without water. All plants and animals have a high water content in their bodies.

About 70 percent of the human body consists of water. We take in water through food and drink, and lose it in the form of urine, sweat and exhaled air.

Water also helps regulate temperature. In hot weather, we drink more water to maintain a stable body temperature. Sweat, which evaporates from the surface of our skin, absorbs heat and thus cools the body.

In plants, water is essential for germination of seed and their growth as well. It also helps to transport nutrients from the soil, and food from the leaves to different parts of the plants. Plants use water, along with carbon dioxide from the air, to make food in the presence of sunlight.

It is essential for cooking and washing.

It is used in dams to generate electricity.

Large amounts of water are used in agriculture and industries.

Water is also used as a medium of transport.

Water serves as a habitat for many plants and animals. water heats up or cools down more slowly which helps to control its temperature and allows aquatic life to survive extreme hot or cold conditions.

Simple Machine ( Machine We Use ) - Class 5 Science - New St. Mery English School

In our daily life, we do many tasks like lifting heavy objects, cutting things, opening a bottle, or drawing water from a well. Some of these tasks are hard to do using only our hands. To make our work easier and faster, we use simple machines.

Simple machines are tools that help us do work with less effort. They do not change the amount of work done, but they make work easier by changing the direction or size of the force. Examples of simple machines include the lever, pulley, wheel and axle, inclined plane, screw, and wedge.

Simple Machine ( Machine We Use ) - Class 5 Science - New St. Mery English School

 1-What is force?

Ans:- The push or pull of an object is called force. It is a physical quantity that can change the  speed, state, direction and dimension of an object.

2-How many types of force?

Ans:- There are four types of force
1- Muscular force
2- Gravitational force
3- Magnetic force
4- Friction force

3-What is Muscular force?

Ans:- The force which is exerted by muscles of the body is called muscular force.
Ex:- running, walking, lifting etc. 

4-What is Gravitational force?

Ans:- Gravitational force is a force that attracts a body towards the centre of the earth or towards any other physical body having mass.

Ex:- leaves and fruits fall from a tree downwards towards the ground due to the gravitational force.

5-What is magnetic force?

Ans:- The force exerted between two magnets or a magnet and a magnetic material is called magnetic force.

6-What is friction force?

Ans:- Friction force is the force that generated when two surfaces rub against one another. It is the force which oppose the relative motion between the two surface that are In contact with each other.

7-What is energy?

 

Ans:- The ability to do work is called energy.

8-Write two uses of light energy?

Ans:-  Light energy helps us to see things.
           Plants use light energy to make food 

9-Write two uses of heat energy?

 

Ans:- Heat energy is used to cook food.
          Heat energy is used to change water to steam.

10-What is the use of electric energy?

 

Ans:- Electric energy is used to run washing machine, refrigerator, fan, iron. It is also used in running train and in industries.

11-What is machine?

Ans:- Anything that makes our work easier and faster by reducing the force is called machine. It helps us to do a great deal of work with less effort.

12:- Write three advantage of machines?

Ans:- The three advantages of machines are
1- Machines help us to do work easily and with less effort.
2- machines help us to do work in less time.
3- Machines make our life easy and comfortable.

13-How many types of machine?

Ans:- There are two types of machine.
1- Simple machine
2- Complex machine

14-What is Simple machine?

Ans:- The devices which have moving or no moving parts that are used to modify motion and the magnitude of force in order to perform work is called simple machine.

15-How many types of simple machine?

Ans:- There are six types of simple machine.
1- lever
2- inclined plane
3- wedge
4- screw
5- wheel and axel
6- pulley

16-What is fulcrum?

 

Ans:- A fixed point around which a lever move is called fulcrum.

17-What is load?

 Ans:- The weight that is to be lifted by the lever is called load.

18-What is effort?

Ans:- The force that is applied on the lever is called the effort.

19-What is load arm?

 

Ans:- The arm between the load and fulcrum is called load arm.

20-What is effort arm?

 Ans:- The arm between the effort and fulcrum is called effort arm.

21-What is lever?

 Ans:- A simple machine that is made of a rod and a fulcrum and it is free to move through a fixed point called fulcrum is called lever.

22-How many types of lever?

 

Ans:- There are three types of lever
1- class 1 lever or (first class lever)
2- class 2 lever or (second class lever)
3- class 3 lever or (third class lever)

23-What is class 1 lever?

 

Ans:- The lever in which the fulcrum is between the load and the effort is called class 1 lever.
Ex- seissors, see-saw, pliers

24-What is class 2 lever?

 

Ans:- The lever in which the load is between the fulcrum and the effort is called class 2 lever.
Ex- Bottle opener, Nut cracker etc.

25-What is class 3 lever?

 Ans:- The lever in which the effort is between the fulcrum and the load is called class 3 lever.
Ex- tweezer, fishing rod, broom, arm etc.

26-What is pulley?

 Ans:- A pulley is a device consisting of a grooved wheel over which a rope or a chain is pulled in order to lift heavy objects. A single fixed pulley does not increase or decrease force. It simply changes the direction of the force.

27-How many types of pulley?

Ans:-  There are four types of pulley.
1- fixed pulley
2- movable pulley
3- Compound system pulley
4- Complex system pulley 

28-What is wheel and axle?

 

Ans:- The wheel and axle is a simple machine having a wheel and an axel. The wheel is attached to the axle so that the force is transferred from one to another

29-What is inclined plane?

Ans:-  An inclined plane is a rigid sloping surface over which heavy loads can be raised or lowered to a certain height or depth. Steeper the inclined plane, greater will be the effort required to push up the load.
Ex:- sloping ramps, flyovers, roads on hills, etc.

30-Write two advantages of inclined plane.

 

Ans:- The two advantages of inclined plane are
1- Inclined plane is used to load heavy things on trucks.
2- Inclined plane is used in hospital as ramp to carry patients.

31-What is wedge?

Ans:- A wedge is double inclined plane. It is made up of two inclined planes joined together in such a way that sharp edge is formed.
Ex:- a knife, an axe, etc.

32-What is screw?

 

Ans:- A screw is a simple machine that appears like an inclined plane which have a wounded thread around a rod with a pointed tip.

33-What is thread?

 Ans:-The winding edge around the screw is called thread.

34-What is screw driver?

 

Ans:- A device that is used to screwed the screw into wood is called screw driver.

What is Complex Machine?

Ans:- A combination of two or more simple machine that work together is called complex machine.

Ex:- cart, cycle etc.

Write five things That we should follow while handling machine

Ans:- The five things That we should follow while handling machine are

1- Take care as moving parts of machine can cause injury.

2- Stay away from the place where heavy loads are being lifted by pulleys.

3- Machine parts should be lubricated time to time.

4- Hold sharp objects away from your body.

5- Always store tools in tool box to keep them and yourself safe.