The Food We Eat - Class 4 Science - New St. Mery English School

Food is an essential part of our life. It gives us energy to play, study, and do our daily activities. Without food, we cannot grow or stay healthy. Different types of food provide different nutrients that help our body to grow, repair, and stay strong.

In our daily life, we eat a variety of foods such as fruits, vegetables, grains, milk, and pulses. Each type of food has its own importance. Some foods give us energy, some help in growth, and others protect us from diseases.

In this lesson, we will learn about the different types of food, their sources, and the importance of eating a balanced diet. This will help us understand how to make healthy food choices and take care of our body.

The Food We Eat - Class 4 Science - New St. Mery English School

What is Food?

Ans:- any substance that we eat or drink to get energy, grow, and stay healthy is called food.

What are Nutrients? Name them.

Ans:- The invisible components that are present inside the food to repair our body, provides us energy and protects us from diseases  are called nutrients of food. The nutrients of food are carbohydrates, proteins, fats, vitamins and minerals etc.

What is energy giving food?

Ans:- The food that provides us energy to work and play is called energy giving food. Energy giving food is rich in carbohydrates and fats. 

Ex:- cereals, potatoes, sugar, sweets, chocolates, ghee, butter, oil etc.

What is body building food?

Ans:- The food that helps our body to grow and rebuild the tissue is called body building food. body building food is rich in proteins. Proteins make our muscles strong.

Ex:- Egg, Meat, Cheese, Fish, Chicken, milk etc.

What is protective food?

Ans:- The food that protects us from many diseases is called protective food. Protective food is rich in vitamins and minerals.

Ex:- Fruits, Vegetables, milk, eggs, curd, almonds, jaggery etc.

What is Roughage?

Ans:- Food that contains fivres is called roughage. It is essential for the digestion of food. Fibres help us to remove waste materials out of our body.

Ex:- fruits, vegetables, seeds etc.

What is use of water in our body?

Ans:- Water helps the body to digest and absorb the food. It regulates the body temperature and also helps in excretion. We should consume 8 to 10 glasses of water daily.

What is Balanced diet?

Ans:- A diet that contains various nutrients, roughage and water in right proportions required for good health is called a balanced diet.

How many methods of cooking food?

Ans:- There are five methods of cooking food?

     1- Boiling

     2- Frying

     3- Roasting

     4- Baking

     5- Steaming

Write some food items that are cooked by Boiling.

Ans:- Rice, pulses, potatoes, eggs and several green vegetables

Write some food items that are cooked by Frying.

Ans:- Puris, Chips, Fried Potatoes etc.

Write some food items that are cooked by Roasting.

Ans:- Groundnuts, Brinjal, Roasted potato, Roasted Chicken etc.

Write some food items that are cooked by Baking?

Ans:- Cakes, Biscuits, Puddings, Pizzas etc.

Write some food items that are cooked by Steaming.

Ans:- Idli, Dhokla, Momos, Rice etc.

What is food preservtion? Write some ways of preserving food?

Ans:- the process of preventing food from rotting by slowing down the growth of germs is called Food Preservation. Some ways of preserving food are Drying, Pickling, Refrigerating, Bottling, Boiling, Deep Freezing.

What are junk foods? Give some example.

Ans:- Some food are not good for our health even if they are very testy are called junk foods

Ex:- Chips, Burger, Chocolate, Samosa, Momos, Pizza, cold drink etc.

Why do we need exercise and games?

Ans:- We need exercise and games to make us healthy and feet. 

Living and Non - Living Things - Class 3 Science - New St. Mery English School

Everything around us can be divided into two main groups – living things and non-living things. Living things, such as plants, animals, and humans, have life. They grow, breathe, move, eat food, and reproduce. On the other hand, non-living things like rocks, water, air, and toys do not have life. They do not grow, breathe, or need food.

Understanding the difference between living and non-living things helps children learn more about the world around them. It also helps them observe nature carefully and develop curiosity about how things work. In this lesson, we will explore the characteristics of living things and identify examples of both living and non-living things in our daily life in a simple and fun way.

Living and Non - Living Things - Class 3 Science - New St. Mery English School 

1:- What are living things ?

Ans:- The things that are alive are called living things.

Ex: - humans beings,  animal,  birds,  insects and plants 

2:- What are non living things?

Ans: - Things that are not alive are called non living thing things

Ex:-  stones,  rocks,  mountains and soil 

3:- Write six characteristics of living things .

 Ans: – the six characteristics of living things are

• Living things move.
• Living things breathe.                 
• Living things need food and water for survival.
• Living things grow.
•  Living things feel.
• Living things reproduce.

3:- Write five characteristics of Non - living things .

 Ans: – the five characteristics of Non - living things are

• Non - Living Things do not have life.
• Non - Living Things do not require food, water or air.               
• Non - Living Things do not breathe.
• Non - Living Things do not grow.
• Non - Living Things do not move from one place to another.

4:- What locomotion

Ans:- movement of animals from one place to another place  is called locomotion

5:- What we call the movement of these living being?
 human , deer , kangaroo , rabbit , monkey , insects and bird.

Ans:- The movement of human is called walk.   
The movement of deer is called walk .

The movement of kangaroo is called hop. 
The movement of rabbit is called hop. 
The movement of monkey is called swing.

The movement of insect is called fiy and crawl. 
The movement of bird is called fiy

The movement of fish is called swim

The movement of snails, snake and earth worm is called crawl

6:- Write the name of a plant that turns their face towards the sun

Ans:-   sun flower

7:- Why do living things need food and water?

Ans:- Living  things need  food  and  water  to  live  and  to  get  energy  to  carry  out  different   work

8:- How do animals get there food

Ans:- Animals get there food directly or indirectly from plants. Cow, deer and sheep get food directly to the plant.  While lion and tiger get their food indirectly to the plants

9:- How does plant make their food

Ans:- plants make their food using sunlight, carbon dioxide, chlorophyll and water. this is called photo synthesis.

10:- By which organ  these  living beings  breathe ( cow, cat, dog, man, fish, insects, plant)

Ans:- Cow, cat, dog and man breathe through lungs.

Fish breathe through gills.

Insects breathe through spiracles present on their body.

Plant breathe through stomata

11:- How many sense organs we have to feel the objects around us ?

Ans:- We have five sense organs to feel the object around us. They are eyes, nose, tongue and skin

12:- What is reproduction ?

Ans:- All living beings reproduce other living beings of their own kind is called reproduction

13:- Write the process how these living beings reproduce their young ones. (human beings , animals , birds, plants)

Ans:- Human beings reproduce their young ones by giving birth.

Animals  reproduce their young ones by giving birth.

Birds reproduce their young ones by laying eggs.

Plants reproduce their young ones Through seeds and From plant parts .

 Types of Plants - Class 2 Science - New St. Mery English School

Plants are an important part of our environment and help us in many ways. They give us food, oxygen, medicine, and make our surroundings beautiful and green. In Class 2 Science, students learn about different types of plants based on their size and how they grow.

Plants are mainly divided into herbs, shrubs, trees, climbers, and creepers. Each type of plant has its own special features. Some plants are small with soft stems, while others are big and strong. Some plants need support to grow, while some spread on the ground.

In this lesson, we will explore all these types of plants in a simple and easy way with examples, so that students can understand and remember them better.

Types of Plants - Class 2 Science - New St. Mery English School

What are Trees? Write five example.

Big and strong plants are called trees. They have strong and woody stem.

Ex:- Mango tree, Banyan tree, Peepal tree, Neem tree, pine tree  etc.

What are Shrubs? Write five example.

Small plants that have woody and hard stems are called Shrubs. They have many bushy branches.

Ex:- Rose plant, Hibiscus plant, Cotton plant, Lemon plant, Tea plant   etc.

What are Herbs? Write five example.

Small plants with soft and green stems are called Herbs.

Ex:- Tulsi, mint, coriander, Spinach, grass, Wheat etc

What are Climbers? Write five example.

Some plants have weak stem. They need support to stand straight, Such plants are called Climbers.

Ex:- Pea plant, Money plant, Grapevine, Bean plant, Pumpkin plant  etc.

What are Creepers? Write five example.

Plants that grow along the ground are called Creepers

Ex:- Watermelon, pumpkin, gourd, Muskmelon, Bottle gourd  etc.

What are water plants? Write five example.

Plants that grow in water are called water plants. They are also called aquatic plants.

Ex:- Lotus, Hydrilla, waterlily, water hyacinth, water chestnut, water stargrass  etc.

What are Desert plants? Write five example.

Plants which grow in desert are called desert plants.

Ex:- Cactus, date, Palm, acacia, prickly pear etc.

What are thorny plants? Write five examples. 

Ans:- Some plants have thorns on their stems and branches. They are called thorny plants.

Ex:- Rose, Prickly pear , Cactus, lemon, babool

What are Non-green plants?

Plants which do not have chlorophyll are called Non-green plants.

Ex:- Mushroom, moulds etc.

 Living And Non-Living Things - Class 1 Science - New St. Mery English School

Our world is full of many different things around us. Some things are alive, like plants, animals, and human beings, while others are not alive, like tables, chairs, and toys. Living things can grow, breathe, move, and need food and water to live. On the other hand, non-living things do not grow, do not breathe, and do not need food or water.

In this topic, we will learn how to identify living and non-living things and understand their basic differences in a simple and fun way. This will help students observe their surroundings carefully and know more about the world they live in.

Living And Non-Living Things - Class 1 Science - New St. Mery English School

1:- What are living things? Write five examples. 

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

Ex:-  snake,  tree,  fish,  horse,  man

2:- What are non-living things? Write five examples.

Ans:- Things which have no lives are called non-living things.

Ex:- book, building , aeroplane, car,  pen

 

3:- What are natural things? Write five examples.

Ans:- Things that are made by nature are called natural things.

Ex:- river, forest , animal, mountain,bird

 

4:- What are man made things? Write five examples.

Ans:- Things that are made by man are called man made things.

Ex:- computer, car , building, aeroplane, table

5:- Write five features of living things.

Ans:- The five features of living things are

1- Living things grow .

2- Living things move on their own .

3- Living things die.

4- Living things feel .

5- Living things reproduce .

 

6:- Write five different between living things and non-living things. 

Ans:- The five different between living things and non-living things are:-

1- Living things grow but Non-living things do not grow. 

2- Living things move on their own but Non living things do not move on their own. 

3- Living things need food, air and water But Non-living things do not need food, air and water. 

4- Living things feel but Non-living things do not feel. 

5- Living things reproduce But Non-living things do not reproduce.

Weather And Season - Class 1 Science - New St. Mery English School

Weather and Season are important topics in Class 1 Science that help children understand the environment around them. Weather tells us about the condition of the air at a particular time, such as whether it is sunny, rainy, windy, or cloudy. Seasons are the different periods of the year that bring changes in weather. The main seasons are summer, winter, rainy season, and spring. Each season has its own special features and affects how we dress, what we eat, and the activities we do.

In this lesson, students will learn the meaning of weather and seasons in simple words. They will also understand the different types of weather, the names of seasons, and how seasons change during the year. This topic helps young learners observe nature and understand how the environment changes over time. It makes learning science easy, interesting, and enjoyable for Class 1 students. 🌤️🌧️❄️🌸

 Weather And Season - Class 1 Science - New St. Mery English School

What is Weather?

Ans:- The day to day conditions of any place are called Weather.

How many types of Weather?

Ans:- There are five types of Weather.

1- Sunny Day

2- Cold Day

3- Cloudy Day

4- Windy Day

5- Rainy Day

What is Season?

Ans:- When one type of weather stay for months, It is called Season.

How many types of season?

Ans:- There are five types of season.

1- Winter Season

2- Spring Season

3- Summer Season

4- Rainy Season

5- Autumn

What should we wear in winter season?

Ans:- Woollen Clothes

What should we wear in Summer season?

Ans:- Cotton clothes

What should we wear in Rainy season?

Ans:- Rain coat or Umbrella

The Solar System - Class 4 Science - New St. Mery English School

The Solar System is a fascinating family of the Sun and the objects that move around it. At the center of the Solar System is the Sun, which gives us heat and light. Around the Sun, there are eight planets that travel in fixed paths called orbits. These planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

Our planet Earth is the only planet known to support life. Besides planets, the Solar System also includes moons, asteroids, and comets. All these heavenly bodies are held together by the Sun’s strong gravitational force.

In this chapter, we will learn about the Sun, the planets, and other interesting objects in space. Let us explore the amazing world of the Solar System and discover how our planet fits into this big universe! 

The Solar System - Class 4 Science - New St. Mery English School

What is Solar System?

Ans:- The Solar System is a group of the Sun and all the objects that move around it like planets, satellites etc.

What is sun?

Ans:- The Sun is a huge, hot ball of gases that is present at the center of solar system. It gives us light and heat, which makes life on Earth possible.

What are planets?

Ans:- The large celestial bodies that revolve around the sun on a fixed path and do not have their own light are called planets.

How many planets in solar system?

Ans:- There are eight planets in solar system. 

1- Mercury 

2- Venus

3- Earth 

4- Mars

5- Jupiter

6- Saturn

7- Uranus

8- Neptune 

Mercury - It is nearest planet to the sun. It is smallest and very hot during the day and very cold at night. 

Venus- It is second planet from the sun. It is the hottest and the brightest planet ,also called 'the morning and the evening star'. It also does not have any moon.

Earth:- It is the third planet from the sun. It is the only planet where life exists. It has all the suitable conditions to support life about seventy percent of Earth's surface is covered with water,so it is also called blue planet . The earth has one moon.

Mars:- It is fourth planet from the sun , also known as 'red planet's. It look red in colour. It has two moon.

Jupiter:- It is the fifth planet from the sun. It is the largest planet of the solar system. It has about 79 moons.

Saturn:- It is the second largest planet, sixth from the sun. It has seven wide rings around it which are made up of ice and dust . It has 62 know moons.

Uranus:- It is the third largest planet ,seventh from the sun.it has 27 known moons.

Neptune:- It is the eighth planet from the sun. It is the coldest planet in the solar system. Neptune has around 14 moons.

What are satellites?

Ans:- The object that revolve around a planet in an orbit is called satellite.

What is moon? 

Ans:- Moon is the natural satellite of the earth. It completes one revolution around the earth in 27 day. The moon does not have its own light but it reflects the light of the sun. It shines at night because of sun's light.

Write three feature of moon?

Ans:- three feature of moon.

1- It does not have the atmosphere as the earth has.

2- there is no water on the moon.

3- The surface of the moon is made up of rock and many mountains and crater.

What are artificial satellites? 

Ans:- The man - made object which move around a planet in an orbit are known as artificial satellites.

Which is the first artificial satellites of world?

Ans:- first artificial satellites was the sputnik-1 , launched by USSR on October 4,1957.

Which is the first artificial satellites of India?

Ans:- first artificial satellites Indian satellite was aryabhata. The launched on April 19,1975.

Write three uses of artificial satellites?

Ans:- three uses of artificial satellites are:

1- they are used to study weather conditions planets and stars.

2- they help in communication through telephone, radio and TV.

3- they are used in GPS ( global positioning system). 

What are stars?

Ans:- the number of twinkling objects that are appear in night sky are called stars.

Why does stars seer to be very small?

Ans:- stars are many times larger than the planets but they seems to very small because they are very far away from us.

Who is the nearest star to the earth?

Ans:- the sun is the nearest star to the earth .

What are constellation?

Ans:- the group of stars that from patterns in the sky are called constellation.

Ex:- ursa, major, ursa minor, Orion etc.

How many types of movement of earth? 

Ans:- there are two types of movement of earth.

1- revolution 

2- rotation 

What is orbit?

Ans:- the earth moves on a fixed path around the sun. This fixed path is called an orbit.

What is revolution?

Ans:- the movement of the earth around the sun in an orbit is called revolution. It takes 365 days to complete one revolution.

What is rotation?

Ans:- the earth spins on its own axis just like a top rotation on its pin. This is called rotation of the earth. It takes 24 days for the earth to complete one rotation.

Write two effects that eauses due to earth's movement ?

Ans:- the two effects that eauses due to earth's movement are.

1- the rotation of the earth causes day and night.

2- season are caused due to revolution of the earth around the sun.

Who divided the earth into two parts?

Ans:- the epuator divided the earth into two halves, called the northern hemisphere and the southern hemisphere.

Light And Shadow - Class 5 Science - New St. Mery English School

Light is an important part of our daily life. Without light, we would not be able to see anything around us. The Sun is the main natural source of light, while bulbs, candles, and tube lights are artificial sources of light. When light falls on an object, it can pass through, get blocked, or form a shadow.

In this chapter, we will learn how shadows are formed and why they change in size and shape. We will also understand the difference between transparent, translucent, and opaque objects. Fun activities and simple examples will help us explore how light travels and how shadows are created in our surroundings.

Light And Shadow - Class 5 Science - New St. Mery English School

What is Light?

Ans:- Light is a form of energy that helps us see things.

What are sources of light?

Ans:- The things that produce their own light are called sources of light.

Ex:- bulb, sun, stars etc 

How many types of sources of light?

Ans:- There are two types of sources of light.

1- Natural sources of light

2- Artificial sources of light

What are Natural sources of light?

Ans:- Natural sources of light are things in nature that produce their own light without being made by humans.

Ex:- Sun, Stars, glow worm etc.

What are Artificial sources of light?

Ans:- The man made things that produce light are called Artificial sources of light.

Ex:- electric bulb, torch, candles etc.

Write three properties of light?

Ans:- Three properties of light are

1- Light travels in straight line. This is called rectilinear propagation of light.

2- Light travels from one place to another.

3- White light is made up of seven colours.

What is Rainbow?

Ans:- When sunlight passes through rain drops, It splits into seven colours and makes a band of seven colours. This band of seven colours are Rainbow. It forms in the sky. The seven colours of rainbow are violet, indigo, blue, green, yellow, orange, and red (VIBGYOR)

How many types of objects on the basis of amount of light they allow to pass through them?

Ans:- There are three types of objects on the basis of amount of light they allow to pass through them.

1- Transparent objects

2- Translucent objects

3- opaque objects

What are transparent objects?

Ans:- Some objects that allow light to pass through them easily are called transparent objects.

Ex:- glass, water etc.

What are translucent objects?

Ans:- Objects through which only some light can pass are called translucent objects.

Ex:- Butter paper, frosted glass, thin cloth, oiled paper

What are opaque objects?

Ans:- Some objects that do not allow light to pass through them are called opaque objects.

Ex:- wood, stone etc.

What is shadow?

Ans:- A shadow is a dark patch formed when an object blocks the path of light. It is always formed on the opposite side to the source of light.

Write three conditions that is necessary for the formation of shadow.

Ans:- The three conditions that is necessary for the formation of shadow are

1- A light source

2- An opaque object

3- A surface such as wall, floor, table top etc.

Write five properties of shadow.

Ans:- The five properties of shadow are

1- The shadow is formed when light falls on an opaque or translucent object.

2- A shadow is formed on the opposite side of the source of light.

3- Shadow do not depend on the colour of the object. It is mostly black.

4- A shadow shows only the shape of the object and not its details.

5- The size of the shadow depends on the distance between the source of light and the object.

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.

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.