NCERT Solutions for Class 6 Science Chapter 10 Motion and Measurement of Distances

 Chapter 10

Motion and Measurement of Distances

 

1. Give two examples each of modes of transport used on land, water and air.
Ans: (i) Land —Bus, truck, train.
        (ii) Water—Ship, boat.
        (iii) Air   —Aeroplane, Helicopter.

2. Fill in the blanks:
(i) One metre is 100 cm.
(ii) Five kilometre is 5000 m.
(iii) Motion of a child on a swing is periodic motion.
(iv) Motion of the needle of a sewing machine is periodic motion .
(v) Motion of wheel of a bicycle is circular motion.

3. Why can a pace or a footstep not be used as a standard unit of length?
Ans: Because a pace or a footstep of each and every person is not equal.

4. Arrange the following lengths in their increasing magnitude :
1 metre, 1 centimetre, 1 kilometre, 1 millimetre.
Ans: Ascending order of length:
1 millimetre < 1 centimetre < 1 metre < 1 kilometre

5. The height of a person is 1.65 m. Express it in cm and mm.
Ans: (a) 1 metre = 100 cm
              1.65 m = 1.65 x 100 cm

              = 165 cm
         (b) 1 metre = 1000 mm

               1.65m = 1.65 x 1000 mm

               = 1650 mm.

6. The distance between Radha’s home and her school is 3250 ,m. Express this distance in km.
Ans : 1km = 1000 m
Hence 3250 m = 3.25 kms

7. While measuring the length of a knitting needle, the reading of the scale at one  end is 3.0 cm and at the other end is 33.1 cm. What is the length of the needle?
Ans:  Length of the needle = 33.1 cm – 3.0 cm = 30.1 cm.

8. Write the similarities and differences between the motion of a bicycle and a ceiling fan that has been switched on.
Ans: (i) Similarity: Both the wheel of a bicycle and a ceiling fan exhibit motion on a fixed axis.
(ii) Dissimilarity: Bicycle moves forward thus executes rectilinear motion but fan does not show such motion.

9. Why could you not use an elastic measuring tape to measure distance? What would be some of the problems you would meet in telling someone about a distance you measured with an elastic tape?
Ans:  An elastic measuring tape gives incorrect length of the distance between two points.
Reasons:
(i) The length of the elastic tape varies and depends upon the force by which it is stretched.
(ii) Measurement would vary between 2 or 3 readings even when measured by the same person and by the same elastic tape.
(iii) Measurement would also vary if different persons measure the same distance.

10. Give two examples of periodic motion.
Ans: (i) Oscillations of a pendulum.
(ii) Motion of swing/motion of earth round the sun.

Workbook Class 6 Science Chapter 9 The Living Organisms and Their Surroundings

 Chapter 9 

The Living Organisms and Their Surroundings

 

I. Answer the following questions in brief:

Q.1. How do plants and animals living in water breathe?

Ans. Plants and animals living in water can breathe air or take oxygen from dissolved oxygen in water.

Q.2. Why do camels have long legs?

Ans. The camels long legs helps to keep their bodies further away from hot ground.

Q.3. What is acclimatization?

Ans. The process of changes that can occur in an organism over a short period of time that helps it to adjust to it surroundings is known as acclimatization.

Q.4. What is the use of needle like leaves to the trees in mountains?

Ans. The needle like leaves to the trees in mountains help in a) reduce transpiration. b) sliding off the snow c) absorbing sunlight.

Q.5. Why do lions eyes in front of the face?

Ans. The lion has eyes in front of the face because they can find their prey easily when they are too far or near like deers, zebra, etc. 

Q. 6. Why do deer have eyes on the side of the head?

Ans. A deer has eyes on the sides of its head because this enables the animals to see predators approaching from the side as well as from behind.

Q. 7. Why do some aquatic plants have narrow and thin ribbon like leaves?

Ans. Some aquatic plants have a narrow & thin ribbon like leaves, so that they can easily bend with flowing water.

Q. 8. Photosynthesis in plants occurs during the day. When does respiration take place in them?

Ans. Respiration takes place in them all the time - both day and night.

Q. 9. Why is is warm inside a sack of wheat?

Ans. Because the seeds inside the sack of wheat respire and they give out some heat.

Q. 10. How does adaptation lead to variety of organisms in different habitats?

Ans. Living organisms are adapted to different. This means that the way they look, the way they behave, how they are built, or their way of life makes them suited to survive and reproduce in their habitats. Behavior is also an important adaptation. Animals inherit many kinds of adaptive behavior.

Q. 11. How do squids and octopuses adapt to living in sea? Give any three points.

Ans. a) These animals have gills to help them use oxygen dissolved in water.

b) Their tentacles allow them to catch any prey.

c) When they move in water they make their body shapes streamlined.

Q. 12. Name any two animals that live in water but not have gills. How do they then survive in it?

Ans. The two aquatic animals without gills are dolphins and whales. These animals come to the water surface in order to breathe as they can't breathe underwater without gills. Whales and dolphins are mammals and they breathe air into their lungs.

II. Give one term for each of the following:

(a) Changes in our surroundings that make us respond to them Stimuli.

(b) The surroundings where an organism lives Habitat.

(c) The presence of specific features or habits which enable an organism to live in its surroundings. Adaptation.

(d) Animals like lions that hunt for their prey. Predators

(e) The process of getting rid of wastes by living beings Excretion

(f) Non-living component of a habitat. Abiotic

III. Fill in the blanks:

(a) Respiration is needed by organisms to obtain energy from the food they consume.

(b) Ponds, lakes, rivers and oceans are example of aquatic habitats.

(c) Predators hunt for their Prey

(d) The process of producing more of their kind of living organisms is called reproduction.

(e) Fish breathe through gills under water.

(f) Whales breathe in air through nostrils called blowhole.

IV. State whether True or False

(a) Deer have eyes in front of the face to have a correct idea about the location of their predator. False

(b) Acclimatization is another form of adaptation. False

(c) Non-Living things do show some characteristics of living organisms. False

(d) Dolphins can breathe under water. False

(e) The mountain goat has strong hooves for running up the rocky slopes of the mountains. True

(f) Some harmful or poisonous materials do get produced in plants as wastes. True

V. Match the following:

(a) Stimulus - (vii) Response

(b) Fish - (v) Gills

(c) Excretion - (iv) Secretions

(d) Potato - (ii) Energy

(e) Respiration - (iii) Birds & (vi) Nostrils

(f) Frog - (i) Webbed feet

VI. Select the correct alternative:

(i) Which of them do/does NOT have a streamlined body?

Ans (c) Squid

(ii) The plant whose leaves fold when someone touches them is 

Ans (c) Mimosa

(iii) The fleshy part of the cacti is 

Ans (a) stem

(iv) Which of the following is NOT necessary for an organism to live?

Ans (d) All of these are necessary

(v) Trees in mountain regions have needle like leaves

Ans (c) to help the rainwater and snow to slide off easily

(vi) Which of the following help(s) a camel to the conditions in a desert?

Ans (d) All of these

 

H.W. (VII) Complete the following word-puzzle using the clues given below:

Class 8 Chapter 6 Let’s Learn Photoshop

Chapter 6
Let’s Learn Photoshop

D. Answer in short.

Que 1. Name the three kinds of Eraser in Photoshop.
Ans - There are three types of Eraser in Photoshop.
Eraser Tool: To erase all those areas of an image on which we drag the mouse pointer.
Background Eraser Tool: To erase the background color from a layer of an image.
Magic Eraser Tool: To erase the areas of an image that share common color pixels.

Que 2. What is Photoshop?
Ans – Adobe Photoshop or simply called Photoshop is a photo editing software. It is used to edit, manipulate and recolor photographs and create special effects.
 
Que 3 How do you start Photoshop?
Ans - To start Photoshop–
Step 1: Click on Start button.
Step 2: Select Adobe Master Collection CS6.
Step 3: Click on Adobe Photoshop CS6.


E. Answer in detail.

Que 1. Write the use of Magic Wand Tool.
Ans - The Magic Wand is one of Photoshop's most powerful selection tools. It is a selection tool and used to quickly select the area of an image with a similar color just by single click.

Que 2. What is the use of Crop Tool? How do you crop an image?
Ans – The Crop Tool is used to keep only the selected part and remove the remaining portion.
Step 1: Click on Crop Tool.
Step 2: Drag over on the image to select the part of our image to be
retained. A cropping border will appear on the image. If we want to
change the selection size, we can use the crop handles.
Step 3: Press Enter key to Crop.

Que 3. How is Lasso Tool different from Marquee Tool?
Ans – The Marquee Tool provides various options to select the area of an image. It can be in rectangular, circular, elliptical or square shapes. The Lasso Tool is used for making a freehand selection. It helps to quickly select image along its edges.

Chapter 6 Formatting Slides in PowerPoint (Class 5)

Chapter 6
Formatting Slides in PowerPoint

D. Answer these questions.

Que 1. What is the use of built-in templates in PowerPoint?
Ans - Templates contain layouts, colors, fonts, effects, background styles for slides. PowerPoint offers many built-in templates.

Que 2. How will you add additional text in your slide?
Ans - To add additional text in your slides we use text box option.
      Step 1: Click on Insert tab.
      Step 2: Click on Text box option.
      Step 3: Drag the mouse pointer on the slide where we want to add the text.
      Step 4: Enter the text as needed.

Que 3. Write the steps to insert slides in a presentation.
Ans - We can insert new slides in a presentation.
      Step 1: Click on Home tab.
      Step 2: Click on New Slide.
      Step 3: Choose and click on a type of layout for the slide.

Que 4. What is the use of Align text?
Ans - Align text command is used to align the text between top and bottom edges of the placeholder. The options are Top, Middle and Bottom.

Chapter 6 Computer Memory (Class 4)

Chapter 6
Computer Memory

E. Answer these questions.

Que 1. Name the two types of computer memory.
Ans - There are two types of memory devices:

• Primary memory devices
• Secondary memory devices.

Que 2. What is the use of secondary memory? Give any two examples.
Ans - Secondary memory is needed in the computer to store data or information for a long period of time. Examples are CD, DVD, Blu-ray, pen drive, memory card, hard disk, etc.

Que 3. Write any one difference between RAM and ROM.
Ans - The difference between RAM and ROM are

	RAM	ROM
1	RAM Stands for Random Access Memory.	ROM Stands for Read Only Memory.
2	RAM store data or information temporary.	ROM store data or information permanently.
3	It is Volatile memory.	It is Non-volatile memory.

Que 4. Why are pen drives more popular than CDs/DVDs?
Ans - Pen drives are more popular than CD/DVDs because it is a portable storage device that can carried in a pocket and storage capacity of pen drive is much higher than CD/DVD.

Que 5. What is a byte?
Ans - A byte of memory is used to store a single character (a letter or a number). 1 byte is equal to 8 bits.

Que 6. What is a hard disk? What is its maximums storage capacity?
Ans -  Hard disk is the main secondary storage device that stores large amount of data permanently. Its maximums storage capacity is 5 TB.

Que 7. What is the use of SSD?
Ans - SSD (Solid State Drive) is a latest technology use to stores data permanently which has begun to replace the hard disk. It is  3 times faster than the hard disk but, it is little expensive than a hard disk.

NCERT Solutions for Class 6 Science Chapter 9 The Living Organisms and Their Surroundings

Class 6 

Chapter 9 

The Living Organisms and Their Surroundings

1. What is a habitat?
Ans: The surroundings where animals live is called their habitat. The organisms depend on their habitat for their food, water, air, shelter and other needs. Habitat means a dwelling place.

2. How are cactus adapted to survive in a desert?
Ans: Cactus are adapted to survive in a desert as they have

(i) Spiny leaves to prevent water loss through transpiration.
(ii) Stem is modified in such a way that it performs photosynthesis and conserves water.
(iii) Their roots go very deep into the soil for absorbing water.

3. Fill in the blanks:
(a) The presence of specific features which enables a plant or an animal to live in a particular habitat is called adaptation.
(b) The habitats of the plants and animals that live on land are called terrestrial habitats.
(c)The habitats of plants and animals that live in water are called aquatic habitats.
(d) Soil, water and air are the abiotic factors of a habitats.
(e) Changes in our surroundings that make us respond to them are called stimuli.

4. Which of the things in the following list are non-living?

Plough, Mushrooms, Sewing machine, Radio, Boat, Water, Hyacinth, Earthworm. 

Ans: Plough, Sewing machine, Radio, Boat and water are non-living.

5. Give an example of a non-living thing which shows any two characteristics of living thing.
Ans: Example of non-living thing is cloud which shows following two characteristics of living things:
(i) It grows in size
(ii) It shows movement.

6. Which of the following non-living things were once part of a living thing?

Butter, Leather, Soil, Wool, Electric Bulb, Cooking Oil, Salt, Apple, Rubber.
Ans: Butter, Leather, Wool, Cooking oil, Apple and Rubber are the non-living things which were once part of a living thing.

7. List the common characteristics of living things.
Ans: Some common characteristics of living things are:

• Growth
• Movement
• Reproduction
• Respiration
• Responsiveness
• Excretion

8. Explain why speed is important for survival in the grasslands for animals that live there. (Hint: There are few trees or places for animals to hide in grasslands habitats).
Ans: In grasslands habitats, there are few trees or places for animals to hide. When their enemy attacks they have to run faster so as to reach a safe place. If they fail, they lose their life. So, the speed is very important for survival of grassland animals.