Category: Class 7

Std 7 Science Chapter 4 Nutrition in Living Organisms Question Answer Maharashtra Board

Balbharti Maharashtra State Board Class 7 Science Solutions Chapter 4 Nutrition in Living Organisms Notes, Textbook Exercise Important Questions and Answers.

Class 7 Science Chapter 4 Nutrition in Living Organisms Question Answer Maharashtra Board

1. Classify according to food-type.
Tiger, cow, vulture, bacteria, deer, goat, human, fungus, lion, sparrow, buffalo, frog, cockroach, tick.
Answer:

• Carnivores: tiger, Lion
• Herbivores: cow, deer, goat, buffalo
• Scavengers: vulture
• Decomposers: fungus, bacteria
• Granivores: sparrow
• Insectivores: frog Parasitic: tick
• Omnivores: human, cockroach

2. Nutrition In Living Organisms Class 7 Exercise Match the pairs.

Class 7 Science Chapter 4 Nutrition In Living Organisms Question Answer Question 1.

Answer:

3. Answer the following questions in your words. 

Question a.
Why do living organisms need nutrition?
Answer:
Living organisms need nutrition due to the following: (a) To supply the energy required for doing work, (b) For growth and development of the body, (c) To replace the damaged cells and repair tissues, (d) To fight diseases.

Question b.
Explain the process of production of food in plants.
Answer:
1. Green plants can produce their own food. With the help of sunlight and chlorophyll, plants make their own food in their leaves, using water and nutrients from the soil and carbon dioxide from the air.

2. This process is called as photosynthesis. In this process plants give out oxygen and take in carbon dioxide.

Question c.
What is meant by parasitic plants? Name their different types with examples of each.
Answer:
The plants that grow on the body of other plants to obtain food are called as parasitic plants.

There are two types of parasitic plants:

• Holoparasites: e.g. Rafflesiaceae
• Hemiparasites: e.g. Loranthaceae

Question d.
Explain the various steps of nutrition in animals.
Answer:
Steps of nutrition in animals are as follows:

1. Ingestion: Food is taken into the body.
2. Digestion: Conversion of food into simple soluble forms.
3. Absorption: Transfer of soluble food to the blood.
4. Assimilation: Utilization of absorbed food by cells and tissues for energy production, growth and repair.
5. Egestion: Removal of waste products and undigested food from body.

Question e.
Name some unicellular organisms in which all life processes take place within their unicellular body.
Answer:
Unicellular organisms like amoeba, euglena, paramoecium in which all life processes take place within their unicellular body.

4. Give reasons.

Question a.

Insectivorous plants are attractively coloured.
Answer:

1. Insectivorous plants generally grow in soil or water deficient in nitrogen compounds.
2. The plant body of the Drosera burmanii has a flower like appearance. It grows close to the ground. Even its leaves are attractively pink or red in colour with hairs at the margin.
3. Droplets of a sticky substances found on tips of the hairs attract insects.
4. These plants consume insects to fulfill their need for nitrogen. To attract the insects these plants are attractively coloured.

Question b.
Butterflies have a long tube-like proboscis.
Answer:
Holozoic mode of nutrition means the feeding of solid and liquid food by animals. Butterflies live on nectar from flowers. Therefore to suck the nectar from flowers, they have a long tube-like structure called proboscis.

5. Prepare and complete the flowchart according to type of nutrition.

Question a.
Prepare and complete the flowchart according to type of nutrition.

Answer:

6. Think and answer.

Question a.
We prepare a variety of foodstuffs and dishes at home. Are we then autotrophic organisms?
Answer:

1. We prepare a variety of foodstuffs and dishes at home but we are not autotrophic organisms.
2. In autotrophic organisms they have chlorophyll in their body and food is prepared here with help of sunlight, water and CO₂ for the organisms.
3. But the food which we prepare at home is not generated in our body.

Question b.
Which organisms are greater in number – autotrophs or heterotrophs? Why?
Answer:

1. Autotrophs have chlorophyll in the cell and here the organic food is prepared using sunlight, water and CO₂.
2. They do not depend on any other organism for survival.
3. But the heterotrophs depend on autotrophs and other organisms for survival. Hence autotrophs are more in number than heterotrophs.

Question c.
The number of heterotrophs found in desert regions is smaller. However, they are found in greater numbers in the sea. Why is this so?
Answer:

1. In desert region due to scarcity of water and excess heat, very few cactus are found as autotrophs compared to sea. As autotrophs are less, number of heterotrophs dependent on autotrophs are smaller.
2. Whereas in sea due to greater numbers of autotrophs, greater number of heterotrophs are found.

Question d.
What damage or harm do ectoparasitic and endoparasitic animals cause?
Answer:

1. Ectoparasitic animals suck the blood of the animal on which it remains and endoparasitic animals get readymade food from the body of animal in which it remain.
2. This way both the parasites make the animal weak by sucking their blood or by eating prepared food from them.

Question e.
Why is plant food not produced in any other parts of the plant except the green ones?
Answer:
Plant food is not produced in any other parts of the plant except the green ones because only green part contains chlorophyll and chlorophyll is very necessary for the production of food.

Class 7 Science Chapter 4 Nutrition In Living Organisms Project:

Question 1.
Many heterotrophic organisms live on one and the same plant. Observe one such plant in your neighborhood and find out about the heterotrophs that depend upon it for their food. Observe and make flotes about other organisms that use these heterotrophs as their food.

Question 2.
Prepare a Power point presentation on the topic ‘Nutrition in Living Organisms’.

Class 7 Science Chapter 4 Nutrition in Living Organisms Important Questions and Answers

Nutrition In Living Organisms Class 7 Exercise Fill in the blanks.

Nutrition In Living Organisms Class 7 Exercise Question 1.
Leaves have microscopic openings called ……………. .
Answer:
Stomata

Class 7 Science Chapter 4 Nutrition In Living Organisms Question 2.
In the process of photosynthesis plants take in ……………. and ……………. gas is given out.
Answer:
Carbondioxide, oxygen

Question 3.
The ……………. transports minerals and water from roots to all aerial parts of the plant.
Answer:
xylem

Question 4.
The ……………. transports the food from the leaves to other parts of the plant.
Answer:
phloem

Question 5.
Plants produce ……………. by the process of photosynthesis.
Answer:
Carbohydrates

Question 6.
……………. are made from carbon, hydrogen, oxygen.
Answer:
Carbohydrates

Question 7.
……………. are made from carbon, hydrogen and oxygen and nitrogen.
Answer:
proteins

Question 8.
……………. plants contain rhizobium micro-organisms.
Answer:
leguminous

Question 9.
Micro-organisms like ……………. are present in soil.
Answer:
azotobacter

Question 10.
Lichen is of a symbiosis between ……………. and ……………. .
Answer:
algae, fungi

Question 11.
The scientist ……………. identified Drosera plant in Sri Lanka in 1737.
Answer:
Johannes Burman

Question 12.
Fungi like mushroom and yeast are ……………. .
Answer:
saprophytes

Question 13.
Removal of waste products and undigested food from the body is called …………….
Answer:
Egestion

Question 14.
Amoeba moves with the help of ……………. .
Answer:
pseudopodia

Question 15.
Butterflies suck food with a tube like ……………. .
Answer:
proboscis

Question 16.
The ……………. or ……………. is an ant eating animal found in India.
Answer:
bobcat, udmanjar

Question 17.
Seed eating animals are called ……………. .
Answer:
granivores

Question 18.
Fruit eating animals are called ……………. .
Answer:
frugivores

Question 19.
Animals that obtain their food from both plants and animals are called ……………. .
Answer:
Omnivores

Question 20.
Roundworms are known as ……………. .
Answer:
endoparasites

Class 7 Science Chapter 4 Nutrition In Living Organisms Match the column:

Question 1.

Answer:

Say whether true or false, correct and rewrite the false statements.

Question 1.
Bed bug is an example of endoparasitic nutrition.
Answer:
False, Bed bug is an example of ectoparasitic nutrition

Question 2.
Spider shows saprozoic nutrition.
Answer:
True

Question 3.
The anteater is found in India.
Answer:
False. The anteater is found in Central and South America

Question 4.
Yellowing of leaves occur due to deficiency of iron.
Answer:
True

Question 5.
Mushroom is used in making bread.
Answer:
False. Yeast is used in making bread

Question 6.
Cuscuta is completely a parasitic plant.
Answer:
True

Question 7.
The nitrogen dioxide dissolves in rainwater and is converted into nitric acid.
Answer:
True

Question 8.
Micro-organism Rhizobium is found in soil.
Answer:
False. Micro-organism Azotobacter is found in soil.

Question 9.
Fixation of nitrogen occurs by biological and atmospheric methods.
Answer:
True

Question 10.
The chloroplasts present in the leaves contain chlorophyll.
Answer:
True

Question 11.
Decomposers obtain their food from living organisms.
Answer:
False, They obtain their food by decomposing the dead bodies of organisms or other materials

Question 12.
Carbondixode is given out during the process of photosynthesis.
Answer:
False, Oxygen is given out during the process of photosynthesis

Question 13.
Phloem transports the food from leaves to other parts of the plant.
Answer:
True

Question 14.
Carbohydrates are made up of carbon, hydrogen oxygen and nitrogen.
Answer:
False, Protein are made up of carbon, hydrogen, Oxygen and nitrogen.

Give scientific reasons.

Question 1.
Micro-organisms like Rhizobium are useful.
Answer:

1. Rhizobium micro-organisms are useful because plants cannot take gaseous nitrogen from air.
2. These micro-organisms absorb atmospheric nitrogen and convert it into its nitrate, a compound which is useful for plant.

Question 2.
Lichen is an example of a symbiotic nutrition.
Answer:
Lichen is a symbiosis between algae and fungi in which fungi provides water, minerals, as well as shelter to algae and in return the algae Master Key General Science (Std. 7), provide food to the fungi. So Lichen, is an example of symbiotic nutrition.

Question 3.
Drosera burmanii is an insectivorous plant.
Answer:
Drosera burmanii grows in a soil which has nitrogen deficiency. It feeds upon insects to obtain nitrogen, so it is an insectivorous plant.

Question 4.
Human is an omnivore.
Answer:
Humans obtain their food from both, plants and animals so human is an omnivore.

Question 5.
Tapeworm is an endoparasite.
Answer:
Tapeworm lives inside the body of other animals and obtain its food. So tapeworm is an endoparasite.

Question 6.
Decomposers are important for the ecosystem
Answer:
Decomposers feed on dead and decaying matter and therefore indirectly clean the ecosystem. If decomposers were not there then nutrients would not be able to return back and get recycled. Therefore decomposers are very important for the ecosystem.

Question 7.
Cuscuta is a total parasite while Loranthus is a partial parasite.
Answer:
Cuscuta is a nongreen yellow thread-like plant completely dependent on the host plant, loranthus is a partial parasitic because it can prepare its own food and it only takes water and minerals from the host plant.

Answer the following in your own words:

Question 1.

Classify the types of nutrients.
Answer:
There are two types of nutrients.

1. Nutrients like carbohydrates, proteins and fats are required in large quantity. These are macro-nutrients.
2. Minerals and vitamins are required in very small quantity. They are called micro-nutrients.

Question 2.
Explain the types of nutrition.
Answer:
There are two types of nutrition.

1. Some organisms can produce their own food and thus nourish themselves. This is called autotrophic nutrition.
2. Some organisms depend on other organisms, plants and animals for their food. This is called heterotrophic nutrition.

Question 3.
Write differences between xylem and phloem.
Answer:

Question 4.
What is chemosynthesis? Which plants produce their food by chemosynthesis?
Answer:

1. Chemosynthesis is the biological conversion of one or more carbon-containing molecules and nutrients into organic matter.
2. It uses the oxidation of inorganic compounds or methane as a source of energy rather than sunlight.
3. Sulphur bacteria and nitrosomonas produce their food by chemosynthesis.

Question 5.
Name the micro-organisms which help in biological fixation of nitrogen. How?
Answer:
Two different types of micro-organisms can bring about biological nitrogen fixation.

1. Root-nodules of leguminous plants contain the micro-organism rhizobium. These micro-organisms absorb atmospheric nitrogen and convert if into its nitrate, a compound.
2. Micro-organisms like azotobacter are’present in soil. They also convert atmospheric nitrogen into nitrates.

Question 6.
What is symbiotic nutrition? Give one example of it.
Answer:

1. Two or more than two different types of plant live together to fulfill their needs of nutrition, protection, support etc. with each other’s help. This type of nutrition is called symbiotic nutrition.
2. e.g. Lichen is an example of symbiosis between algae and fungi.

Question 7.
Write about Drosera burmanii.
Answer:

1. It is art insectivorous plant.
2. The scientist Johannes Burman identified this plant in Sri Lanka in 1737. Hence, the plant is named after him.
3. It grows close to the ground.
4. Its leaves are attractively pink or red in colour with hairs at the margin.
5. Droplets of a sticky substance found at the tips of the hairs attract insects.
6. It grows in a place where deficiency of nitrogen in the soil. To get nitrogen for its growth, it eats insects.

Question 8.
What are called saprophytic plants? Give Examples.
Answer:
Plants which obtain the food from dead and decaying bodies of other organisms are called saprophytic plants e.g. Yeast and mushrooms.

Question 9.
Classify the animals according to the type of food they eat.
microbes, vulture, monkey, tiger, lion, goat, cow, buffalo, crow, hyena, human, chimpanzee
Answer:

• Herbivores: goat, cow, buffalo.
• Carnivores: tiger, lion
• Omnivores: monkey, human, chimpanzee
• Scavengers: vulture, crow, hyena
• Decomposers: microbes

Explain the terms:

1. Herbivores: Animals that depend on plants only for their food are called Herbivores.
2. Carnivores: Animals that depend on other animals for their food are called Carnivores.
3. Granivores: Animals that eat grains (seed) are called Granivores.
4. Frugivores: Animals that eat fruits are called frugivores.
5. Omnivores: Animals that obtain their food from both plants and animals are called omnivores.
6. Scavengers: Animals that obtain their food from dead bodies of animals are called Scavengers.
7. Decomposers: Microbes which obtain their food by decomposing the dead bodies of organisms or other materials are called decomposers.
8. Ectoparasitic nutrition: Some animals live on the body surface of other animals and obtain their food by sucking their blood. This is called ectoparasitic nutrition.
9. Endoparasitic nutrition: Some animals live inside the body of other animals and obtain their food. This is called endoparasitic nutrition.
10. Symbiotic nutrition: In some cases, two or more than two different types of plants live together to fulfill their needs of nutrition, protection, support etc. with each other’s help. This type of nutrition is called symbiotic nutrition.

Write the role of different nutrients like nitrogen, phosphorus, potassium,magnesium, Iron, manganese and zinc and effects of their deficiency on plants.

Question 1.
Write the role of different nutrients like nitrogen, phosphorus, potassium, magnesium, Iron, manganese and zinc and effects of their deficiency on plants.
Answer:
Role of nutrients and effects of their deficiency on plants:

Can you tell?

Answer the following question: 

Question 1.
How does ingestion occur in unicellular animals like amoeba?
Answer:

1. Amoeba does not have organs like hands and mouth.
2. It is a unicellular animal. It can take in food through any part of the surface of its unicellular body.
3. It surrounds the food particle from all sides to take it into the cell.
4. After that it digests the food with the help of different enzymes.
5. Undigested food is left behind as the amoeba moves further with the help of pseudopodia.
6. In unicellular animals like amoeba, euglena, paramoecium,. etc. all the steps of nutrition occur within their unicellular body.

Question 2.
How do plants produce their own food?
Answer:
Green plants produce their own food with the help of sunlight, chlorophyll, water, nutrients from soil and carbon dioxide from the air. This process is called as photosynthesis

Use your brain power!

Answer the following questions:

Question 1.
Write the uses of yeast and mushrooms.
Answer:
Yeast is used in fermentation processes and making bread.
Mushrooms are a rich source of vitamins and iron.

Question 2.i
Which part of the loranthus plant carries out photosynthesis?
Answer:
Leaves of the loranthus plant carries out photosynthesis.

Question 2.ii
From where do they obtain minerals and water?
Answer:
They obtain water and minerals from the xylem and phloem of the other host plant.

Question 2.iii
Why is loranthus known as a partially parasitic plant?
Answer:
Loranthus is known as partially parasitic plant because it does photosynthesis with the help of leaves but only for water and minerals it depends on other plants.

Question 3.
Why does the pitcher plant feed on insects even though it produces food by photosynthesis?
Answer:
Pitcher plants grow in a place where soil has deficiency of nitrogen compounds so to fulfill the need of nitrogen they feed on insects.

Observe the diagram and answer the following questions.

Question a.
Name the process shown in the picture.
Answer:
The process shown is photosynthesis.

Question b.
Which type of plants use the above process for their nutrition?
Answer:
Autotrophic plants (green plants) use the above process for their nutrition.

Question c.
What is the pigment in the leaf that helps in the above process?
Answer:
Chlorophyll

Question d.
Give the chemical equation of the above process?
Answer:

Question e.
What is the importance of this process to living things?
Answer:
Photosynthesis helps the plants to prepare their own food and also store it in their plant bodies. Animals depend upon this stored food for their nutrition.
During photosynthesis, oxygen is given out which is important for all living organisms for respiration.

Observe the diagram and answer the following questions.

Question a.
What is shown in the picture?
Answer:
Roots of leguminous plants having root nodules.

Question b.
What is the importance of these types of plants?
Answer:
These types of plants help to provide nitrogen to the soil.

Question c.
What is the process called?
Answer:
Biological Nitrogen fixation

Question d.
Explain the process.
Answer:
Root nodules of leguminous plants contain Rhizobium micro-organisms. These micro¬organisms convert atmospheric nitrogen into nitrates. Thus the soil becomes rich in nitrogen.

Maharashtra State Board Class 7 Science Textbook Solutions

• The Living World: Adaptations and Classification Class 7 Science Textbook Solutions
• Plants: Structure and Function Class 7 Science Textbook Solutions
• Properties of Natural Resources Class 7 Science Textbook Solutions
• Nutrition in Living Organisms Class 7 Science Textbook Solutions
• Food Safety Class 7 Science Textbook Solutions
• Measurement of Physical Quantities Class 7 Science Textbook Solutions
• Motion, Force and Work Class 7 Science Textbook Solutions
• Static Electricity Class 7 Science Textbook Solutions
• Heat Class 7 Science Textbook Solutions
• Disaster Management Class 7 Science Textbook Solutions

Std 7 Science Chapter 5 Food Safety Question Answer Maharashtra Board

Balbharti Maharashtra State Board Class 7 Science Solutions Chapter 5 Food Safety Notes, Textbook Exercise Important Questions and Answers.

Class 7 Science Chapter 5 Food Safety Question Answer Maharashtra Board

1. Complete the following statements by using the correct option from those given below.
(Irradiation, dehydration, pasteurization, natural, chemical)

Question a.
Drying the food grains from farms under the hot sun is called …………. .
Answer:
dehydration

Question b.
Materials like milk are instantly cooled after heating up to a certain high temperature. This method of food preservation is called ……….. .
Answer:
pasteurization

Question c.
Salt is a ……….. type of food preservative.
Answer:
natural

Question d.
Vinegar is a …………. type of food preservative.
Answer:
chemical

2. Answer the following questions in your own words. 

Question a.
How is milk pasteurised?
Answer:
Boil the milk at 80°C for 15 minutes and cool it quickly. This destroys the microbes present in the milk and it can remain for a longer duration. This process is called pasteurization of milk.

Question b.
Why should we not consume adulterated food materials?
Answer:
Different types of adulterants affect our health in different ways. Some adulterants cause abdominal discomfort or poisoning while some may affect the functioning of some organs if consumed over a long period of time or even cause cancer.

Question c.
What precautions do your parents take to keep foodstuffs safe?
Answer:
Our parents take following care to keep foodstuffs safe

1. Drying of grains.
2. Boiling of milk, soups and curries from time to time.
3. Refrigeration of vegetables, fruits, milk and cooked food.
4. Candying of jams.
5. Use natural preservatives like oil, spices, neem leaves, salt, etc.
6. Use chemical preservatives in sauces, ketchups, pickles, jams and squashes.

Question d.
How does food spoilage occur? Which are the various factors spoiling the food?
Answer:
Food spoilage is the process in which food deteriorates to the point in which it is not edible to humans or its quality of edibility becomes reduced.
Following are the factors for spoiling of food:

1. Bacteria causes food to spoil
2. Incorrect storage may spoil the food.
3. Infestation by pests.
4. Chemical reaction takes place in food and it gets spoiled.

Question e.
Which methods of food preservation would you use?
Answer:
I use following methods to preserve the food:

1. Freezing
2. Boiling
3. Salting of pickles
4. drying of grains
5. candying of jams.

3. What shall we do?

Question a.
There are vendors selling uncovered sweet-meats in open places in the market.
Answer:
We should tell them to sell the covered sweets because uncovered sweets are harmful to eat because it contains dust, dirt and germs. And buyers also should not purchase these uncovered sweets.

Question b.
A ‘pani-puriwala’ is serving the panipuri with dirty hands.
Answer:
We should tell him to wear gloves before serving panipuri because dirty hands contain dirt and germs which are harmful to us.

Question c.
We have purchased a large quantity of fruits and vegetables.
Answer:
We should keep them in refrigerator because in refrigerator, due to low temperature, fruits and vegetables do not spoil and biological and chemical reactions in fruits and vegetables are slowed down at low temperature.

Question d.
We need to protect foodstuffs from pests like rats, cockroaches, wall-lizards etc.
Answer:

1. If we do not protect foodstuffs from pests like rats, cockroaches, wall-lizards etc. then the food get spoiled by them and germs carried by them enters into the food.
2. If we eat this food then we may get food poisoning and we fall sick so we need to protect foodstuffs from pests like rat, cockroaches, wall lizards etc.

4. Find the odd-man-out. 

Question a.
Salt, vinegar, citric acid, sodium benzoate.
Answer:
Salt

Question b.
Lakhi dal, brick dust, metanyl yellow, turmeric powder.
Answer:
Turmeric powder

Question c.
Banana, apple, guava, almond.
Answer:
Almond

Question d.
Storing, freezing, settling, drying
Answer:
Storing

5. Complete the chart below.

Question a.

Answer:

6. Explain why this happens and suggest possible remedies.

Question a.
Qualitative wastage of food.
Answer:
Qualitative wastage of food happens due to wrong methods of protecting food, excessive use of food preservatives, over-cooking, washing the vegetables after cutting them, mis¬handling of fruits like grapes and mangoes, miscalculation of the time required to transport food from producers to consumers are some of the reasons of qualitative wastage of food.
Possible remedies:

1. Avoid overcooking of food.
2. Store grains and other perishable foodstuffs like vegetables, fruits, milk etc. using proper methods.
3. Wash fruits and vegetables before cutting it.

Question b.
The cooked rice is underdone.
Answer:
Sometimes in a hurry if we cook the rice it is underdone.
Possible remedies: Use proper pressure cooker to cook the rice.

Question c.
The wheat that was bought is a bit moist.
Answer:
Sometimes due to sudden rain, wheat gets a bit moist. Possible remedies: Do not store the moist wheat, it gets spoiled due to fungus so first sundry it and then store in a clean and dry container to avoid microbial growth.

Question d.
The taste of yoghurt is too sour/slightly bitter.
Answer:
The taste of yoghurt is too sour/slightly bitter means it is spoiled. This happens if it is not kept in the refrigerator.
Possible remedies:- Always keep the yoghurt in refrigerator to avoid biological and chemical reactions in food materials.

Question e.
Cut fruits turned black.
Answer:
Fruit contains an enzyme called polyphenol oxidase or tyrosinase that reacts with oxygen. The oxidation reaction basically forms a sort of rust on the surface of fruits so it turns black.
Possible remedies:

1. Coat the fruits with sugar syrup
2. Add lemon juice on fruits.

7. Give reasons.

Question 1.
Food remains safe at 5° Celsius.
Answer:
Food remains safe at 5° Celsius because at 5°C, micro-organisms stop growing.

Question 2.
Nowadays, food is served in buffet style during large gatherings.
Answer:
Nowadays, food is served buffet style during large gatherings because due to buffet style quantitative wastage of food can be avoided, as people take only as much as they could eat.

Project:

Question 1.
Go to your kitchen und take notes about the food safety measures and the food wastage you see there.

Question 2.
In a science exhibition demonstrate the various methods of detecting food adulteration.

Class 7 Science Chapter 5 Food Safety Important Questions and Answers

Complete the following statements by using the correct option from those given below.
(Irradiation, dehydration, pasteurization, natural, chemical)

Question 1.
………………………. is celebrated as “World Food Day”.
Answer:
16th October

Question 2.
FSSAI means ………………………. .
Answer:
Food Safety and Standardization Authority of India

Question 3.
………………………. gas is filled in tight packets of potato wafers.
Answer:
Nitrogen

Question 4.
Common name of acetic acid is ……………………….
Answer:
Vinegar

Question 5.
………………………. is sprayed on the gunny bags containing food grains.
Answer:
Melathion

Question 6.
………………………. is used in smoking method.
Answer:
Aluminium phosphide

Question 7.
………………………. and ………………………. are emitted by radioactive isotopes in irradiation method.
Answer:
X – rays, gamma rays

Question 8.
In Maharashtra, irradiation plants have been installed at ………………………. for onions and potatoes and at for spices and condiments.
Answer:
Lasalgaon, Navi Mumbai

Question 9.
………………………. found the pasteurisation method.
Answer:
Louis Pasteur

Question 10.
………………………. adulterant is added to turmeric powder.
Answer:
Metanyl yellow

Question 11.
………………………. adulterant is added to red chilly powder.
Answer:
Brickdust

Question 12.
………………………. is used to make fruits more attractive.
Answer:
calcium carbide

Question 13.
………………………. and ………………………. harmful chemicals are mixed with cold drinks.
Answer:
carbonated soda, phosphoric acid

Question 14.
Shopkeepers change the of the ………………………. food packets fo avoid a financial loss.
Answer:
expiry date

Question 15.
Milk vendors add ………………………. to the milk to appear as higher fat content.
Answer:
urea

Question 16.
The shelf life of potatoes and onions ………………………. due to slowed-down of sprouting.
Answer:
increases

Question 17.
Serving too much food to guests at traditional feasts and banquets leads to ………………………. wastage of food.
Answer:
Quantitative

Question 18.
Miscalculation of the time required to transport food from producers to consumers leads to ……………………… . wastage of food.
Answer:
Qualitative

Question 19.
Prevention of food spoilage by microbial growth and infestation by pests is called ………………………. .
Answer:
food protection

Question 20.
………………………. is an example of a chemical preservative.
Answer:
Sodium benzoate.

Say whether True or False,, Correct and rewrite the false statement.

Question 1.
To prevent adulteration of food, it is inspected by the “Food and Drug Administration department of the government”.
Answer:
True

Question 2.
Overcooking of food increases the quality of food.
Answer:
False. Over cooking of food spoils it

Question 3.
Peanuts become rancid then, it is not good to eat.
Answer:
True

Question 4.
Oil and ghee contain fats.
Answer:
True

Question 5.
Prevention of food spoilage by microbial growth and infestation by pests is called food wastage.
Answer:
False. Prevention of food spoilage by microbial growth and infestation by pests is called food protection.

Question 6.
Serve yourself only as much as you can eat.
Answer:
True

Question 7.
Salt, sugar and oil are naturally available preservatives.
Answer:
True

Question 8.
Pickles can be preserved by salting.
Answer:
True

Question 9.
Milk vendors add urea to the milk so that it appears to have higher fat content.
Answer:
True

Question 10.
Shelf life of fruits and vegetables decreases by gamma rays emitted by radio-active isotopes.
Answer:
False. Shelf life of fruits and ‘ vegetables increases by gamma rays emitted by radioactive isotopes.

Give scientific reasons.

Question 1.
Refrigerators are used in the kitchen.
Answer:

1. Biological and chemical reactions in food materials are slowed down at low temperature.
2. As a result food remains in good condition for a longer period. Therefore refrigerators are used in the kitchen.

Question 2.
Potatoes and onions are treated with gamma rays.
Answer:
Potatoes and onions are treated with gamma rays because irradiation with gamma rays prevents their wastage due to sprouting and increases their shelf life.

Question 3.
Grains are sun-dried.
Answer:
Grains are sun-dried to preserve them because on sun drying their water content gets reduced and hence they last longer.

Question 4.
We boil milk from time to time.
Answer:
We boil milk from time to time to kill microorganisms in it and thus prevent it from getting spoilt.

Question 5.
Jams or pickles get spoilt if their jars are not sealed properly.
Answer:
If the jar is not sealed properly, micro¬organisms from the air enter in the jar and start growing on the food. Oxygen in the air helps the micro-organisms and fungi to grow faster and hence bring about the spoilage of the jams and pickles.

Question 6.
Some vendors add urea to the milk.
Answer:
Some vendors add urea to the milk so that it appears to have higher fat content.

Question 7.
Food wastage should be avoided.
Answer:
In countries like India, the food requirement is plenty and people do not get proper meals even once in a day. If food is not wasted then it could have met the need of many others. Therefore, food should not be wasted and proper measures should be implemented to stop quantitative and qualitative wastage of food.

Question 8.
Adulterated food should not be consumed.’
Answer:

1. The health of all people is endangered by food adulteration.
2. Different types of adulterants affect our health in different ways.
3. Some adulterants cause abdominal discomfort or poisoning, while some may affect the functioning of some organs if consumed over a long period of time or even cause cancer.

Can you tell?

Answer the following questions:

Question 1.
How and where food is wasted?
Answer:
Quantitative wastage of food:
1. Wrong methods of farming like hand sowing of, ts seeds, inadequate threshing, improper storage and wrong methods of distribution are some reasons for quantitative wastage of food.

2. Besides, much food is wasted as a result of the custom of offering and serving too much food to guests at traditional feasts or banquets.

3. Had it not been wasted, all this food could have met the need of many others Qualitative wastage of food: Using wrong methods of protecting food, excessive use of food preservatives, over-cooking, washing the vegetables after cutting them, mis-handling of fruits like grapes and mangoes, mis-calculation of the time required to transport food from producers to consumers, are some of the causes of quantitative wastage of food.

Question 2.
How is the food adulterated?
Answer:
Food is adulterated by the following ways:

1. Removal of some important components of food. e.g. removal of fat content of milk, essence of cloves, cardamoms, etc.
2. Mixing of a low quality inedible or cheaper material or harmful colour with food.
3. Mixing of some harmful materials like small stones, fine sand, iron filings, urea, dung of horse, sawdust etc.

How will you find out if food has been adulterated?

Maharashtra State Board Class 7 Science Textbook Solutions

• The Living World: Adaptations and Classification Class 7 Science Textbook Solutions
• Plants: Structure and Function Class 7 Science Textbook Solutions
• Properties of Natural Resources Class 7 Science Textbook Solutions
• Nutrition in Living Organisms Class 7 Science Textbook Solutions
• Food Safety Class 7 Science Textbook Solutions
• Measurement of Physical Quantities Class 7 Science Textbook Solutions
• Motion, Force and Work Class 7 Science Textbook Solutions
• Static Electricity Class 7 Science Textbook Solutions
• Heat Class 7 Science Textbook Solutions
• Disaster Management Class 7 Science Textbook Solutions

Std 7 Science Chapter 7 Motion, Force and Work Question Answer Maharashtra Board

Balbharti Maharashtra State Board Class 7 Science Solutions Chapter 7 Motion, Force and Work Notes, Textbook Exercise Important Questions and Answers.

Class 7 Science Chapter 7 Motion, Force and Work Question Answer Maharashtra Board

1. Fill ¡n the blanks with the proper words from the brackets.
(stationary, zero, changing, constant, displacement, velocity, speed. acceleration, stationary but not zero. inc reuses)

Question a.
If a body traverses a distance in direct proportion to the time, the speed of the body is ……………… .
Answer:
constant

Question b.
If a body is moving with a constant velocity, its acceleration is ……………… .
Answer:
zero

Question c.
……………. is a scalar quantity.
Answer:
Speed

Question d.
…………….. is the distance traversed by a body in a particular direction in unit time.
Answer:
Velocity

2. Observe the figure and answer the questions.

Sachin and Sarneer started on a motorbike from place A, took the turn at 13, did a task at C, travelled by the route CD to D and then went on to E. Altogether, they took one hour for this journey. Find out the actual distance traversed by them and the displacement from A to E. From this, deduce their speed. What was their velocity from A to E in the direction AE’? Can this velocity be called average velocity?

Question a.
Observe the figure and answer the questions

Sachin and Sarneer started on a motorbike from place A, took the turn at 13, did a task at C, travelled by the route CD to D and then went on to E. Altogether, they took one hour for this journey. Find out the actual distance traversed by them and the displacement from A to E. From this, deduce their speed. What was their velocity from A to E in the direction AE’? Can this velocity be called average velocity?
Answer:
1. Actual distance = \(\overline{\mathrm{AB}}\) + \(\overline{\mathrm{BC}}\) + \(\overline{\mathrm{CD}}\) + \(\overline{\mathrm{DE}}\) = 3 + 4 + 5 + 3
Actual distance = 15 km

2. Displacement = \(\overline{\mathrm{AB}}\) + \(\overline{\mathrm{BD}}\) + \(\overline{\mathrm{DE}}\)
= 3 + 3 + 3
Displacement = 9 km

3. Speed = \(\frac{\text { Distance travelled }}{\text { Total time }}\)
Distance = 15 km = 15 × 1000 = 15000 m
Time = 1 hr = 1 × 60 × 60 = 3600 sec.
s = \(\frac{15000}{3600}\) or s = \(\frac{15 \mathrm{~km}}{1 \text { hour }}\) = 15km/hour
= 4.16 m/sec. or 15 km/hour

4. Velocity = \(\frac{\text { Distance travelled }}{\text { Total time }}\)
Displacement = 9 km = 9 × 1000 = 9000 m
Time = 1 hr = 1 × 60 × 60 = 3600 sec
V = \(\frac{9000}{3600}\) or V = \(\frac{9 \mathrm{~km}}{1 \text { hour }}\) = 9 km/hour
= 2.5 m/sec. or 9 km/hour

5. Yes, this velocity can be called as average velocity.

3. From the groups B and C, choose the proper words, for each of the words in group A.

Question a.
From the groups B and C, choose the proper words, for each of the words in group A.

Answer:

4. A bird sitting on a wire, flies, circles around and comes back to its perch. Explain the total distance it traversed during its flight and its eventual displacement.

Question a.
Answer:
The total distance the bird has traversed is the length of the distance covered by circling, but the eventual displacement are the bird is zero as its initial and final position are one and the same.

5. Explain the following concepts in your own words with everyday examples: force, work, displacement, velocity, acceleration, distance.

Question a.
Explain the following concepts in your own words with everyday examples: force, work, displacement, velocity, acceleration, distance.
Answer:
1. Force: The interaction that brings about the acceleration is called force.
e.g: An ox is pulling a cart, applying brakes to a bicycle, lifting heavy iron object with a crane.

2. Work: When an object is displaced by applying a force on it, work is said to be done.
e.g: A bucketful of water is to be drawn from a well and taken to the home by walking from well to home.

3. Displacement: The minimum distance
traversed by a moving body in one direction from the original point to reach the final point is called displacement.
e.g: A rolling of a ball from point A to point B in the same direction.

4. Velocity: Velocity is the distance traversed by a body in a specific direction in unit time.
e.g: A truck is covering a distance of 40km from A to D in a straight line in 1 hour.

5. Acceleration: It is change in velocity per second. It can be deduced.
Acceleration = \(\frac{\text { Change in velocity }}{\text { Time taken for change }}\)
e.g:

(i) In the above example a truck covered the distance AB at velocity of 60 km/hr, BC at 30 km/hr and CD at 40 km/hr. (ii) It means that the velocity for the distance CD is greater than the velocity for the distance BC. (iii) From the number of seconds required for this change in velocity to take place, the change in velocity per second can be deduced. This is called acceleration (iv) Distance: The length of the route actually traversed by a moving body irrespective of the direction is called distance.
e.g: Ranjit travelled 1km. from his home to school.

6. A ball is rolling from A to D on a flat and smooth surface. Its speed is 2 cm/s. On reaching B, it was pushed continuously up to C. On reaching D from C, its speed had become 4 cm/s. It took 2 seconds for it to go from B to C. What is the acceleration of the ball as it goes from B to C.

Question a.
A ball is rolling from A to D on a flat and smooth surface. Its speed is 2 cm/s. On reaching B, it was pushed continuously up to C. On reaching D from C, its speed had become 4 cm/s. It took 2 seconds for it to go from B to C. What is the acceleration of the ball as it goes from B to C.

Answer:
As its initial and final positions are one and the same.
Initial Velocity = 2 cm/s.
Final Velocity = 4 cm/s
Time taken for the change in velocity from B to
D = 4 cm/s – 2 cm/s = 2 cm/s

7. Solve the following problems.

Question a.
A force of 1000 N was applied to stop a car that was moving with a constant velocity. The car stopped after moving through 10m. How much is the work done?
Answer:
Force (F) = 1000 N
displacement (s) = 10m
work done (W) = ?
W = Fs
= 1000 × 10
W = 10,000 Joule

Question b.
A cart with mass 20 kg went 50 m in a straight line on a plain and smooth road when a force of 2 N was applied to it. How much work was done by the force?
Answer:
Force (F) = 2 N
Displacement (s) = 50 m
Work done (W) = ?
W = Fs
= 2 × 50
W = 100 Joule

Project:

Question a.
Collect information about the study made by Sir Isaac Newton regarding force and acceleration and discuss it with your teacher.

Class 7 Science Chapter 7 Motion, Force and Work Important Questions and Answers

Fill in blanks:

Question 1.
Displacement is a …………. quantity.
Answer:
vector

Question 2.
The …………. of an object can change even while it is moving along a straight line.
Answer:
velocity

Question 3.
The …………. velocity can be different at different times.
Answer:
instantaneous

Question 4.
Change in velocity per second is called …………. .
Answer:
acceleration

Question 5.
The interaction that brings about the acceleration is called …………. .
Answer:
force

Question 6.
The scientist …………. was the first to study force and the resulting acceleration.
Answer:
Sir Isaac Nezvton

Question 7.
Ability to do work is called …………. .
Answer:
Energy

Question 8.
W = …………. × S.
Answer:
F

Question 9.
Unit of work is …………. and …………. .
Answer:
Joule, erg

Question 10.
Unit of force is …………. and …………. .
Answer:
Newton, dyne

Question 11.
Force is a …………. quantity.
Answer:
vector

Question 12.
The velocity at a particular time is called …………. velocity.
Answer:
instantaneous

Question 13.
The …………. of a body is the distance traversed per unit time.
Answer:
speed

Question 14.
Unit of acceleration is …………. and …………. .
Answer:
m/s² and cm/s²

Question 15.
Force is measured by the …………. that it produces.
Answer:
acceleration

Question 16.
Work done by a body with no displacement will be …………. .
Answer:
zero

Say whether True or False, correct the false 1 statements:

Question 1.
Velocity is distance travelled per unit of time.
Answer:
False. Speed is distance travelled per unit of time

Question 2.
In displacement, both distance and direction are taken into account.
Answer:
True

Question 3.
Speed = Distance/time.
Answer:
True

Question 4.
Change in speed per second is acceleration.
Answer:
False. Change in velocity per second is acceleration

Question 5.
Work done depends on the force and the displacement.
Answer:
True

Question 6.
C.G.S. unit of acceleration is m/s².
Answer:
False. C.G.S. unit of acceleration is cm/s².

Question 7.
M.K.S. unit of force is dyne.
Answer:
False. M.K.S. unit of force is Newton

Question 8.
Force is measured by the acceleration that it produces.
Answer:
True

Write the difference between the following:

Question 1.
Speed and Velocity
Answer:

Question 2.
Distance and Displacement
Answer:

Solve the following problems!

Question 1.
A bus travelled 200 km in the first 3 hours and then 100 kms for the next one and a half hours and then 120 kms for the next one and a half hours. What is the average velocity of the bus if it has moved in a straight line for the whole journey.
Answer:

Question 2.
See the diagram and calculate the Distance and Displacement travelled by the body from A to I.

Answer:
Distance travelled =
A → B → C → D → E → F → G → H + I
= 5 + 7 + 6 + 3 + 5 + 4 + 6 + 5
= 41 m
Displacement = A → I in a straight line shortest distance
= 1m

Use your brainpower:

Question 1.
The unit of acceleration is m/s², verify this.
Answer:

Question 2.
Acceleration is a vector quantity. Is force a vector quantity too?
Answer:
Yes, acceleration and force both are vector quantities, because both can be expressed completely only when magnitude and direction are given and the quantity which needs direction and magnitude both is called a vector quantity.

Maharashtra State Board Class 7 Science Textbook Solutions

• The Living World: Adaptations and Classification Class 7 Science Textbook Solutions
• Plants: Structure and Function Class 7 Science Textbook Solutions
• Properties of Natural Resources Class 7 Science Textbook Solutions
• Nutrition in Living Organisms Class 7 Science Textbook Solutions
• Food Safety Class 7 Science Textbook Solutions
• Measurement of Physical Quantities Class 7 Science Textbook Solutions
• Motion, Force and Work Class 7 Science Textbook Solutions
• Static Electricity Class 7 Science Textbook Solutions
• Heat Class 7 Science Textbook Solutions
• Disaster Management Class 7 Science Textbook Solutions

HCF and LCM Class 7 Maths Chapter 3 Practice Set 11 Solutions Maharashtra Board

Balbharti Maharashtra State Board Class 7 Maths Solutions covers the 7th Std Maths Practice Set 11 Answers Solutions Chapter 3 HCF and LCM.

Std 7 Maths Practice Set 11 Solutions Answers

Question 1.
Factorize the following numbers into primes:
i. 32
ii. 57
iii. 23
iv. 150
v. 216
vi. 208
vii. 765
viii. 342
ix. 377
x. 559
Solution:
i. 32

∴ 32 = 2 × 2 × 2 × 2 × 2

ii. 57

∴ 57 = 3 × 19

iii. 23

∴ 23 = 23 × 1

iv. 150

∴ 150 = 2 × 3 × 5 × 5

v. 216

∴ 216 = 2 × 2 × 2 × 3 × 3 × 3

vi. 208

∴ 208 = 2 × 2 × 2 × 2 × 13

vii. 765

∴ 765 = 3 × 3 × 5 × 17

viii. 342

∴ 342 = 2 × 3 × 3 × 19

ix. 377

∴ 377 = 13 × 29

x. 559

∴ 559 = 13 × 43

Class 7 Maths Solution Maharashtra Board

• Multiplication and Division of Integers Practice Set 8 Class 7 Maths Solution
• Multiplication and Division of Integers Practice Set 9 Class 7 Maths Solution
• HCF and LCM Practice Set 10 Class 7 Maths Solution
• HCF and LCM Practice Set 11 Class 7 Maths Solution
• HCF and LCM Practice Set 12 Class 7 Maths Solution
• HCF and LCM Practice Set 13 Class 7 Maths Solution
• HCF and LCM Practice Set 14 Class 7 Maths Solution

Geometrical Constructions Class 7 Maths Chapter 1 Practice Set 1 Solutions Maharashtra Board

Balbharti Maharashtra State Board Class 7 Maths Solutions covers the 7th Std Maths Practice Set 1 Answers Solutions Chapter 1 Geometrical Constructions.

Std 7 Maths Practice Set 1 Solutions Answers

Question 1.
Draw line segments of the lengths given below and draw their perpendicular bisectors:
i. 5.3 cm
ii. 6.7 cm
iii. 3.8 cm
Solution:
i.

Line AB is the perpendicular bisector of seg PQ.

ii.

Line UV is the perpendicular bisector of seg ST.

iii.

Line ST is the perpendicular bisector of seg LM.

Question 2.
Draw angles of the measures given below and draw their bisectors:
i. 105°
ii. 55°
iii. 90°
Solution:
i. 105°

ii. 55°

iii. 90°

Question 3.
Draw, an obtuse-angled triangle and a right-angled triangle. Find the points of concurrence of the angle bisectors of each triangle. Where do the points of concurrence lie?
Solution:

The points of concurrence of the angle bisectors of both the triangles lie in the interior of the triangles.

Question 4.
Draw a right-angled triangle. Draw the perpendicular bisectors of its sides. Where does the point of concurrence lie?
Solution:

The point of concurrence of the perpendicular bisectors of the sides of the right angled triangle lies on the hypotenuse.

Question 5.
Maithili, Shaila and Ajay live in three different places in the city. A toy shop is equidistant from the three houses. Which geometrical construction should be used to represent this? Explain your answer.
Solution:
Since, Maithili, Shaila and Ajay live in three different places, lines joining their houses will form a triangle.
The position of the toy shop which is equidistant from three houses can be found out by drawing the perpendicular bisector of the sides of the triangle joining the three houses.
The shop will be at the point of concurrence of the perpendicular bisectors.

Maharashtra Board Class 7 Maths Chapter 1 Geometrical Constructions Practice Set 1 Intext Questions and Activities

Question 1.
Draw a line segment PS of length 4cm and draw its perpendicular bisector. (Textbook pg. no. 1)

1. How will your verify that CD is the perpendicular bisector? m∠CMS = __°
2. Is l(PM) = l(SM)?

Solution:

1. Here, m∠CMS = 90°
2. Also, l(PM) = l(SM) = 2cm
   ∴ line CD is the perpendicular bisector of seg PS.

7th Std Maths Solution Maharashtra Board

• Geometrical Constructions Practice Set 1 Class 7 Maths Solution
• Geometrical Constructions Practice Set 2 Class 7 Maths Solution
• Geometrical Constructions Practice Set 3 Class 7 Maths Solution
• Geometrical Constructions Practice Set 4 Class 7 Maths Solution
• Geometrical Constructions Practice Set 5 Class 7 Maths Solution
• Geometrical Constructions Practice Set 6 Class 7 Maths Solution
• Geometrical Constructions Practice Set 7 Class 7 Maths Solution

Joint Bar Graph Class 7 Maths Chapter 7 Practice Set 31 Solutions Maharashtra Board

Balbharti Maharashtra State Board Class 7 Maths Solutions covers the 7th Std Maths Practice Set 31 Answers Solutions Chapter 7 Joint Bar Graph.

Std 7 Maths Practice Set 31 Solutions Answers

Question 1.
The number of saplings planted by schools on World Tree Day is given in the table below. Draw a joint bar graph to show these figures.

Solution:

Question 2.
The table below shows the number of people who had the different juices at a juice bar on a Saturday and a Sunday. Draw a joint bar graph for this data.

Solution:

Question 3.
The following numbers of votes were cast at 5 polling booths during the Gram Panchayat elections. Draw a joint bar graph for this data.

Solution:

Question 4.
The maximum and minimum temperatures of five Indian cities are given in °C. Draw a joint bar graph for this data.

Solution:

Question 5.
The numbers of children vaccinated in one day at the government hospitals in Solapur and Pune are given in the table. Draw a joint bar graph for this data:

Solution:

Question 6.
The percentage of literate people in the states of Maharashtra and Gujarat are given below. Draw a joint bar graph for this data.

Solution:

Maharashtra Board Class 7 Maths Chapter 7 Joint Bar Graph Practice Set 31 Intext Questions and Activities

Question 1.
Observe the graph shown below and answer the following questions. (Textbook pg. no. 51)

1. In which year did Ajay and Vijay both produce equal quantities of wheat?
2. In year 2014, who produced more wheat?
3. In year 2013, how much wheat did Ajay and Vijay each produce?

Solution:

1. Both produced equal quantities of wheat in the year 2011.
2. Ajay produced more wheat in the year 2014.
3. Ajay’s wheat production in 2013 = 40 quintal.
   Vijay’s wheat production in 2013 = 30 quintal.

Question 2.
The minimum and maximum temperature in Pune for five days is given. Read the joint bar graph and answer the questions below: (Textbook pg. no. 52)

1. What data is shown on X- axis?
2. What data is shown on Y- axis?
3. Which day had the highest temperature?
4. On which day is the minimum temperature the highest?
5. On Thursday, what is the difference between the minimum and maximum temperature?
6. On which day is the difference between the minimum and maximum temperature the greatest?

Solution:

1. Five days of a week are shown on X – axis.
2. Temperature in the city of Pune is shown on Y – axis.
3. Monday had the highest temperature.
4. The minimum temperature was highest on Wednesday.
5. Maximum temperature = 29.5° C
   Minimum temperature = 15° C
   ∴ Difference in temperature = 29.5° C – 15° C = 14.5 ° C
6. The difference in minimum and maximum temperature is greatest on Thursday.

Question 3.
Collect various kinds of graphs from newspapers and discuss them. (Textbook pg. no. 53)
i. Histogram

ii. Line graph

iii. Pie chart

Solution:
(Students should attempt the above activities on their own.)

Class 7 Maths Solution Maharashtra Board

• Indices Practice Set 26 Class 7 Maths Solution
• Indices Practice Set 27 Class 7 Maths Solution
• Indices Practice Set 28 Class 7 Maths Solution
• Indices Practice Set 29 Class 7 Maths Solution
• Indices Practice Set 30 Class 7 Maths Solution
• Joint Bar Graph Practice Set 31 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 32 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 33 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 34 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 35 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 36 Class 7 Maths Solution

Indices Class 7 Maths Chapter 6 Practice Set 30 Solutions Maharashtra Board

Balbharti Maharashtra State Board Class 7 Maths Solutions covers the 7th Std Maths Practice Set 30 Answers Solutions Chapter 6 Indices.

Std 7 Maths Practice Set 30 Solutions Answers

Question 1.
Find the square root:
i. 625
ii. 1225
iii. 289
iv. 4096
v. 1089
Solution:
i. 625

∴ 625 = 5 x 5 x 5 x 5
∴ √625 = 5 x 5 = 25

ii. 1225

∴ 1225 = 5 x 5 x 7 x 7
∴ √1225 = 5 x 7 = 35

iii. 289

∴ 289 = 17 x 17
∴ √289 = 17

iv. 4096

∴ 4096 = 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2
∴ √4096 = 2 x 2 x 2 x 2 x 2 x 2
= 64

v. 1089

∴ 1089 = 3 x 3 x 11 x 11
∴ √1089 = 3 x 11
= 33

Maharashtra Board Class 7 Maths Chapter 6 Indices Practice Set 30 Intext Questions and Activities

Question 1.
Try to write the following numbers in the standard form. (Textbook pg. no. 48)
i. The diameter of Sun is 1400000000 m.
ii. The velocity of light is 300000000 m/sec.
Solution:
i. 1400000000 m = 1.4 x 10⁹ m
ii. 300000000 m/s = 3.0 x 10⁸ m/sec.

Question 2.
The box alongside shows the number called Googol. Try to write it as a power of 10. (Textbook pg. no. 48)

Solution:
1 x 10¹⁰⁰

Class 7 Maths Solution Maharashtra Board

• Indices Practice Set 26 Class 7 Maths Solution
• Indices Practice Set 27 Class 7 Maths Solution
• Indices Practice Set 28 Class 7 Maths Solution
• Indices Practice Set 29 Class 7 Maths Solution
• Indices Practice Set 30 Class 7 Maths Solution
• Joint Bar Graph Practice Set 31 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 32 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 33 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 34 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 35 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 36 Class 7 Maths Solution

Indices Class 7 Maths Chapter 6 Practice Set 29 Solutions Maharashtra Board

Balbharti Maharashtra State Board Class 7 Maths Solutions covers the 7th Std Maths Practice Set 29 Answers Solutions Chapter 6 Indices.

Std 7 Maths Practice Set 29 Solutions Answers

Question 1.
Simplify:
i. \(\left[\left(\frac{15}{12}\right)^{3}\right]^{4}\)
ii. (3⁴)^-2
iii. \(\left[\left(\frac{1}{7}\right)^{-3}\right]^{4}\)
iv. \(\left[\left(\frac{2}{5}\right)^{-2}\right]^{-3}\)
v. (6⁵)⁴
vi. \(\left[\left(\frac{6}{7}\right)^{5}\right]^{2}\)
vii. \(\left[\left(\frac{2}{3}\right)^{-4}\right]^{5}\)
viii. \(\left[\left(\frac{5}{8}\right)^{3}\right]^{-2}\)
ix. \(\left[\left(\frac{3}{4}\right)^{6}\right]^{7}\)
x. \(\left[\left(\frac{2}{5}\right)^{-3}\right]^{2}\)
Solution:
i. \(\left[\left(\frac{15}{12}\right)^{3}\right]^{4}\)
\(=\left(\frac{15}{12}\right)^{3 \times 4}=\left(\frac{15}{12}\right)^{12}\)

ii. (3⁴)^-2
= 3^4×(-2)
= 3^-8

iii. \(\left[\left(\frac{1}{7}\right)^{-3}\right]^{4}\)
\(=\left(\frac{1}{7}\right)^{(-3) \times 4}=\left(\frac{1}{7}\right)^{-12}\)

iv. \(\left[\left(\frac{2}{5}\right)^{-2}\right]^{-3}\)
\(=\left(\frac{2}{5}\right)^{(-2) \times(-3)}=\left(\frac{2}{5}\right)^{6}\)

v. (6⁵)⁴
= 6^5×4
= 6²⁰

vi. \(\left[\left(\frac{6}{7}\right)^{5}\right]^{2}\)
\(=\left(\frac{6}{7}\right)^{5 \times 2}=\left(\frac{6}{7}\right)^{10}\)

vii. \(\left[\left(\frac{2}{3}\right)^{-4}\right]^{5}\)
\(=\left(\frac{2}{3}\right)^{(-4) \times 5}=\left(\frac{2}{3}\right)^{-20}\)

viii. \(\left[\left(\frac{5}{8}\right)^{3}\right]^{-2}\)
\(=\left(\frac{5}{8}\right)^{3 \times(-2)}=\left(\frac{5}{8}\right)^{-6}\)

ix. \(\left[\left(\frac{3}{4}\right)^{6}\right]^{7}\)
\(=\left(\frac{3}{4}\right)^{6 \times 1}=\left(\frac{3}{4}\right)^{6}\)

x. \(\left[\left(\frac{2}{5}\right)^{-3}\right]^{2}\)
\(=\left(\frac{2}{5}\right)^{(-3) \times 2}=\left(\frac{2}{5}\right)^{-6}\)

Question 2.
Write the following numbers using positive indices:
i. \(\left(\frac{2}{7}\right)^{-2}\)
ii. \(\left(\frac{11}{3}\right)^{-5}\)
iii. \(\left(\frac{1}{6}\right)^{-3}\)
iv. \((y)^{-4}\)
Solution:
i. \(\left(\frac{7}{2}\right)^{2}\)
ii. \(\left(\frac{3}{11}\right)^{5}\)
iii. \(6^{3}\)
iv. \(\frac{1}{y^{4}}\)

Class 7 Maths Solution Maharashtra Board

• Indices Practice Set 26 Class 7 Maths Solution
• Indices Practice Set 27 Class 7 Maths Solution
• Indices Practice Set 28 Class 7 Maths Solution
• Indices Practice Set 29 Class 7 Maths Solution
• Indices Practice Set 30 Class 7 Maths Solution
• Joint Bar Graph Practice Set 31 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 32 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 33 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 34 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 35 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 36 Class 7 Maths Solution

Indices Class 7 Maths Chapter 6 Practice Set 28 Solutions Maharashtra Board

Balbharti Maharashtra State Board Class 7 Maths Solutions covers the 7th Std Maths Practice Set 28 Answers Solutions Chapter 6 Indices.

Std 7 Maths Practice Set 28 Solutions Answers

Question 1.
Simplify:
i. a⁶ ÷ a⁴
ii. m⁵ ÷ m⁸
iii. p³ ÷ p¹³
iv. x¹⁰ ÷ x¹⁰
Solution:
i. a⁶ ÷ a⁴
= a^6-4
= a²

ii. m⁵ ÷ m⁸
= m^5-8
= m^-3

iii. p³ ÷ p¹³
= p^3-13
= p^-10

iv. x¹⁰ ÷ x¹⁰
= x^10-10
= x⁰
= 1

Question 2.
Find the value of:
i. (-7)¹² ÷ (-7)¹²
ii. 7⁵ ÷ 7³
iii. \(\left(\frac{4}{5}\right)^{3} \div\left(\frac{4}{5}\right)^{2}\)
iv. 4⁷ ÷ 4⁵
Solution:
i. (-7)¹² ÷ (-7)¹²
= (-7)^12-12
= (-7)⁰
= 1

ii. 7⁵ ÷ 7³
= 7^5-3
= 7²
= 49

iii. \(\left(\frac{4}{5}\right)^{3} \div\left(\frac{4}{5}\right)^{2}\)
\(=\left(\frac{4}{5}\right)^{3-2}=\frac{4}{5}\)

iv. 4 ÷ 4
= 4^7-5
= 4²
= 16

Class 7 Maths Solution Maharashtra Board

• Indices Practice Set 26 Class 7 Maths Solution
• Indices Practice Set 27 Class 7 Maths Solution
• Indices Practice Set 28 Class 7 Maths Solution
• Indices Practice Set 29 Class 7 Maths Solution
• Indices Practice Set 30 Class 7 Maths Solution
• Joint Bar Graph Practice Set 31 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 32 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 33 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 34 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 35 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 36 Class 7 Maths Solution

Indices Class 7 Maths Chapter 6 Practice Set 27 Solutions Maharashtra Board

Balbharti Maharashtra State Board Class 7 Maths Solutions covers the 7th Std Maths Practice Set 27 Answers Solutions Chapter 6 Indices.

Std 7 Maths Practice Set 27 Solutions Answers

Question 1.
Simplify:
i. 7⁴ × 7²
ii. (-11)⁵ × (-11)²
iii. \(\left(\frac{6}{7}\right)^{3} \times\left(\frac{6}{7}\right)^{5}\)
iv. \(\left(-\frac{3}{2}\right)^{5} \times\left(-\frac{3}{2}\right)^{3}\)
v. a¹⁶ × a⁷
vi. \(\left(\frac{\mathrm{P}}{5}\right)^{3} \times\left(\frac{\mathrm{P}}{5}\right)^{7}\)
Solution:
i. 7⁴ × 7²
= 7⁴⁺²
= 7⁶

ii. (-11)⁵ × (-11)²
= (-11)⁵⁺²
= (-11)⁷

iii. \(\left(\frac{6}{7}\right)^{3} \times\left(\frac{6}{7}\right)^{5}\)
\(=\left(\frac{6}{7}\right)^{3+5}=\left(\frac{6}{7}\right)^{8}\)

iv. \(\left(-\frac{3}{2}\right)^{5} \times\left(-\frac{3}{2}\right)^{3}\)
\(=\left(-\frac{3}{2}\right)^{5+3}=\left(-\frac{3}{2}\right)^{8}\)

v. a¹⁶ × a⁷
= a¹⁶⁺⁷
= a²³

vi. \(\left(\frac{\mathrm{P}}{5}\right)^{3} \times\left(\frac{\mathrm{P}}{5}\right)^{7}\)
\(=\left(\frac{\mathrm{P}}{5}\right)^{3+7}=\left(\frac{\mathrm{P}}{5}\right)^{10}\)

Class 7 Maths Solution Maharashtra Board

• Indices Practice Set 26 Class 7 Maths Solution
• Indices Practice Set 27 Class 7 Maths Solution
• Indices Practice Set 28 Class 7 Maths Solution
• Indices Practice Set 29 Class 7 Maths Solution
• Indices Practice Set 30 Class 7 Maths Solution
• Joint Bar Graph Practice Set 31 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 32 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 33 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 34 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 35 Class 7 Maths Solution
• Algebraic Expressions and Operations on them Practice Set 36 Class 7 Maths Solution