NCERT Solutions for Class 6 Science Chapter 13 Fun with Magnets

Chapter 13

Fun with Magnets

1. Fill in the blanks in the following:

(i) Artificial magnets are made in different shapes such as bar magnets , horse-shoe magnets and  cylindrical magnets.

(ii) The materials which are attracted towards a magnet are called magnetic materials

(iii) Paper is not a magnetic.

(iv) In olden days, sailors used to find direction by suspending a piece of bar magnet.
(v) A magnet always has Two poles. 

2. State whether the following statements are true or false.

(i) A cylindrical magnet has only one pole. False
(ii) Natural magnets were discovered in Greece. False
(iii) Similar poles of a magnet repel each other. True
(iv) Maximum iron filings stick in the middle of a bar magnet when it is brought near them. False
(v) Bar magnets always point towards North-South direction when suspended freely in air. True
(vi) A compass can be used to find East-West direction at any place. True
(vii) Rubber is a magnetic material. False 

3. It was observed that a pencil sharpener gets attracted by both the poles of a magnet although its body is made of plastic. Name a material that might have been used to make some part of it.

Ans - The blade of a pencil sharpener is made of iron which is a magnetic material. Due to this a pencil sharpener gets attracted towards both poles of a magnet. 

4.  Column I shows different positions in which one pole of a magnet is placed near that of the other. Column II indicates the resulting action between them for each situation. Fill in the blanks.

Ans  -
Column I    Column II
N − N          Repulsion
N − S           Attraction
S − N          Attraction
S − S           Repulsion

5. Write any two properties of a magnet.

Ans - Two properties of a magnet are:
(i) A magnet always has two poles: North Pole and South Pole.
(ii) Like magnetic poles repel each other and unlike magnetic poles attract each other. 

6. Where are poles of a bar magnet located?

Ans - Poles of a bar magnet are located at its two ends.

7. A bar magnet has no markings to indicate its poles. How would you find out near which end is its north pole located?

Ans - Take the bar magnet and suspend it freely with the help of a thread, the end that points towards North Pole will be regarded as north end of the magnet. Take a bar magnet with known poles on it. Let the north pole of the magnet be brought closer to the suspended magnet at the end that is pointing towards north, if it show repulsion than it is conformed.

8. You are given iron strip. How will you make it into a magnet?

Ans - Making a magnet: Take an iron strip and place it on the table. Now take a bar magnet and place one of its poles near one edge of the strip of iron. Without lifting it moves it along the length of the iron strip till we reach the other end. Now lift the magnet and bring the pole to the same point of strip where we began. Repeat this process about 30-40 times. Bring some iron fillings near the strip and observe that the strip attracts the fillings. This indicates that the iron strip become magnet. 

9. How is compass used to find direction?

Ans - A compass is a small case of glass. A magnetised needle is pivoted inside the box. The needle can rotate freely. Compass also has a dial with directions marked on it. The compass is kept at the place where we want to know the directions. When needle comes to rest it indicates north-south direction. The compass is then rotated until the north and south marked on the dial are at the two ends of the needle.

NCERT Solutions for Class 6 Science Chapter 12 Electricity and Circuits

Chapter 12
Electricity and Circuits

1. Fill in the blanks:

(a) A device that is used to break an electric circuit is called Switch

(b) An electric cell has Two

2. True or False:

(a) Electric current can flow through metals.  True
(b) Instead of metal wires, a jute string can be used to make a circuit. False
(c) Electric current can pass through a sheet of thermocol. False

3.Explain why the bulb would not glow in the arrangement shown in fig.

Ans - The bulb would not glow in the arrangement shown in figure because the one end of test/screw driver is made up of plastic which does not allow the electric current to flow through it.

4. Complete the drawing shown in Fig. 12.9 to indicate where the free ends of the two wires should be joined to make the bulb glow.

 

Ans -

 


5. What is the purpose of using an electric switch? Name some electrical gadgets that have switches built into them.

Ans - Electric switch is used to make electric circuit open or closed for a particular appliance and hence with the help of a switch we can use an appliance according.

6. Would the bulb glow after completing the circuit shown in Fig. 12.9 if instead of safety pin we use an eraser?

Ans - No, since eraser is an insulator so it does not allow the current to pass. Hence the bulb will not glow.

7. Would the bulb glow in the circuit shown in Fig. 12.11.

 

Ans - Yes, the electric circuit is closed so the bulb will glow.

8. Using the“conduction tester” on an object it was found that the bulb begins to glow. Is that object a conductor or an insulator? Explain.

Ans - Yes, if the object is good conductor of electricity then current will pass through conduction tester and the bulb will glow. Hence the object will be a conductor of electricity. 

9. Why should an electrician use rubber gloves while repairing an electric switch at your home? Explain.

Ans - Our body is good conductor of electricity and rubber is insulator. During repairing work if the body comes in contact with current carrying wire then there will not be any accident as rubber does not allow the passage of current through it. Hence electrician uses rubber gloves while repairing an electric switch.

10. The handles of the tools like screwdrivers and pliers used by electricians for repair work usually have plastic or rubber covers on them. Can you explain why?

Ans - Plastic and rubber is an insulator which does not allow electric current to pass through it. The handles of the tools like screwdrivers and plier used by electricians for repair have covering plastic or rubber so that electric current may not pass through these tools to the body of the electrician to harm him.

Chapter 7 More About Photoshop (Class 8)

Chapter 7
More About Photoshop

A. Tick the correct answer and fill in the blank.

1. The Healing Brush Tool is used to fix imperfections.
2. The Layer palette is on the right side of the Photoshop screen.
3. The Clone Stamp Tool is used to create duplicate part of an image.
4. The Layer palette shows a thumbnail view of the image.
5. The hide a layer, click on the eye icon of the layer.

B. Name of the following tools.

1. Custom Shape
2. Dodge
3. Spot Healing Brush
4. Blur
5. Rectangle
6. Clone Stamp

C. Answer in short.  

Que 1. Name the tool to create shape other than basic shapes.
Ans - Custom shape tool is used to create shape other than basic shapes.

Que 2. What are the ways to apply filters to an image?
Ans – There are two ways to apply filters – directly from the Filter menu or using the Filter Gallery option.

Que 3 What is a layer?
Ans - Layers are like transparent sheets on top of each other.

D. Answer in detail.

Que 1. How do you change the size of an image?
Ans - To change the size of an image–
    Step 1: Open the image to be corrected.
    Step 2: Click on Image menu and select Image Size option. The Image Size dialog box will appear.
    Step 3: Change the Width and Height under the Document Size section.
    Step 4: Click on OK button.
    
Que 2. Write steps to apply filter from Filter gallery to your image.
Ans – To apply filter from Filter gallery to image–
    Step 1: Open the image to add special effects to it.
    Step 2: Click on Filter menu Filter Gallery. The Filter Gallery dialog box will open.
    Step 3: Choose the desired filter from the category and click on OK button.

Que 3.  How can you remove the scratches from the old photographs?
Ans – To remove scratches from old photographs–
    Step 1: Open the file to be edited and select Spot Healing Brush Tool.
    Step 2: Choose a brush size from the Options bar.
    Step 3: Click over the spots to fix imperfections.

Que 4.  How can improve extra dark images?
Ans – To improve extra dark images–
    Step 1: Open the image to be corrected.
    Step 2: Click on Image menu Adjustments Brightness/Contrast. The Brightness/ Contrast dialog box opens.
    Step 3: Increase the Brightness and Contrast values to improve the picture and click on OK button.

Que 5.  Write the use of the following tools:
    a. Dodge         b. Smudge
    c. Blur         d. Clone stamp
Ans – Dodge - Dodge Tool lightens a part of an image.
      Smudge - Smudge Tool spreads color in an image.
      Blur - Blur Tool reduces the sharpness of an image.
      Clone stamp - Clone stamp Tool creates a clone or duplicate part of an image.
      
Que 6.  What is the difference between Healing Brush and Spot Healing Brush Tool?
Ans - Spot Healing Brush tool - It is used to fix imperfections such as scratches, pimples, dark spots, etc.
    Healing Brush tool - It is used to fix imperfections such as wrinkles, scratches, scars, etc. It is different from Healing Brush Tool because unlike Spot Healing Tool, we need to select the source (sampled pixels) with which we want to paint the flawed areas of the image.

Chapter 6 More About Flash (Class 7)

CHAPTER 6
More About Flash

A. Tick the correct answer and fill in the blank.

1. Tweened animation defines the content of the first frame and last frame.
2. In Frame by frame animation, we need to make changes in every frame.
3. Frame controls the period of time of the movie.
4. Symbols are the reusable elements stored in Flash library.
5. Frame by Frame animation is used for creating complex.

B. Write True or False. 

1. Symbols can be inserted only once in a Flash document. False
2. Layers and frames are the part of Properties panel. False
3. Only one instance symbol can be used in Flash document. False
4. Layers once added cannot be removed from the Flash document. False
5. The blank keyframe indicates the current status of movie. False

C. Fill in the blanks.

1. An instance is an copy of a symbol.
2. Animation means a series of images one after another.
3. Shape tweening animation does not work on symbols.
4. Layers are likes sheets of transparent papers arranged in a stack.
5. We create instance of the symbol by selecting it from library  palette and dragging it on the stage.

D. Answer in short.

Que 1 What is a keyframe?
Ans - A keyframe is a frame in which we define a change in an object such as, change in its properties, resizing or rotating it, adding or deleting an object.

Que 2 Which tool is used to rotate an object?
Ans –  Free Transform tool is used to rotate an object.

Que 3 Name the two types of animations.
Ans – There are two types of animations in Flash:
•    Tweened animation
•    Frame by Frame animation.

Que 4 How do you play the movie?
Ans –  We can play the movie by pressing Ctrl and Enter keys or select Control menu Test Movie Test.

E. Answer in detail.

Que 1 Write the difference between Shape Tween and Motion Tween.
Ans – In Motion Tween, the object travels from one point to another and involves no changes of shapes. In Shapes Tween, the object changes its shape over the period of time.

Que 2 What is the use of frame by frame animation? How is it done?
Ans – Frame by frame animation means change of object in each frame, so as to produce an animation sequence. Every frame is a keyframe in frame by frame animation. This type of animation is best suited for complex animations. 

To create an animation of a cartoon using Frame by frame animation–
Step 1: Draw a cartoon.
Step 2: Select frame 2.
Step 3: Insert a keyframe at frame 2.
Step 4: Now, make changes as you like, such as add text, change position of hand, etc.
Step 5: Repeat Step 2 and 3.
Step 6: Test movie by pressing Ctrl and Enter keys.

Que 3 Explain Timeline Panel of Flash.
Ans - Timeline Panel is the area that shows all the elements of animation over time. It is an important component of Flash required to design an animated movie. Timeline is made up of Frames and Layers.

Que 4 Write steps to insert a layer.
Ans - To insert a new layer–
Method 1: Click on New Layer icon from Timeline panel. 

Method 2: Click on Insert menu Timeline Layer.

Que 5  Write steps to convert an object into a symbol.
Ans –  To create a symbol–
Step 1: Select the object.
Step 2: Select Modify menu → Convert to Symbol option. The Convert to Symbol dialog box appears.
Step 3: Type the name and choose the Type –Movie clip, Button or Graphic.
Step 4: Click on OK button. The symbol is added to the library and the objected on the stage becomes an instance of the symbol.

Chapter 6 More About Excel (Class 6)

Chapter 6
More About Excel

A. Tick the correct answer and fill in the blank. 

1. Copy  means duplicating the data.
2. Cut, copy and paste commands are present in Clipboard group.
3. Auto Fill feature allows to fill a series of data automatically.
4. Formula in Excel starts with Equal to (=) sign.
5. Orientation command is used to rotate the contents of a cell.

B. Name these alignment option.

 


C. Identify the following pictures.

1. Cut
2. Copy
3. Paste
4. Undo

D. Write True or False.
 
1. Cell contents cannot be deleted. False
2. Inserting rows or columns changes the size of the worksheet. False
3. Auto Fill feature allows to fill data automatically. True
4. Cell address cannot be used in a formula. False

E. Answer in short. 

1. What is Auto Fill?
Ans – The Auto Fill feature of Excel is used to quickly fill a predefined series of data such as text or numbers in worksheet.

2. What is the use of Merge & Center command?
Ans – The Merge & Center command is used to combine two or more selected adjacent cells to create a single cell.

3. In which tab will find Wrap Text command?
Ans – In Home tab we will find Wrap Text command.

F. Answer in detail. 

1.  How will you insert columns in a worksheet?
Ans – To insert rows/columns: 

Step 1: Select the row to insert a new row above it or select the column to insert a new column to its left.

Step 2: Click on Home tab. 

Step 3: Click on Insert from the Cells group. 

Step 4: Click the Insert Sheet Rows option to insert a new row or Insert Sheet Columns option to insert a new column.

2. Explain the method for moving the data in a worksheet.
Ans – To move the contents of a cell: 

Step 1: Select the cell or range.

Step 2: Click on Home tab.

Step 3: Click on Cut from the Clipboard group. An animated dashed line appears around the cell. 

Step 4: Click on the new cell where you want the content to be moved. 

Step 5: Click on Paste from the Clipboard group.

3. Explain the working of Undo and Redo commands.
Ans – Undo command is used to reverse the last action done. Redo command reverses the thing we have undone. These buttons are found on the Quick Access toolbar.

4. How will you insert a list of months without entering manually?
Ans – To fill day/months: 

Step 1: Enter the first value of day or month in a cell and press the Enter key. Select the cell. 

Step 2: Drag the fill handle to enclose the desired cells to be filled with the series.

5. Explain the difference between Copy and Cut commands.
Ans – We can copy the contents of a cell to other cells by using Copy and Paste commands. We can move the contents of a cell to some other location by using Cut and Paste commands.

NCERT Solutions for Class 6 Science Chapter 11 Light, Shadows and Reflections

Chapter 11

Light Shadows and Reflection

Exercise Questions

Que.1 Rearrange the boxes given below to make a sentence that helps us understand opaque objects.

Ans - The given boxes can be rearranged to form ‘Opaque Objects Make Shadows’ as shown below

Que. 2. Classify the objects or materials given below as opaque, transparent or translucent and luminous or non-luminous:

Air, water, a piece of rock, a sheet of aluminum, a mirror, a wooden board, a sheet of polythene, a CD, smoke, a sheet of plane glass, fog, a piece of red hot iron, an umbrella, a lighted fluorescent tube, a wall, a sheet of carbon paper, the flame of a gas burner, a sheet of cardboard, a lighted torch, a sheet of cellophane, a wire mesh, kerosene stove, sun, firefly, the moon.

Ans - Opaque:  A piece of rock, a sheet of aluminium, a mirror, a wooden board, a CD, an umbrella, a wall, a sheet of carbon paper,  a sheet of cardboard.

Transparent: Air, water, a sheet of plane glass.

Translucent: A sheet of polythene, smoke, fog, a sheet of cellophane, a wire mesh.

Luminous: A piece of red hot iron, a lighted fluorescent tube, the flame of a gas burner, a lighted torch, sun, firefly, kerosene stove.

Non – luminous: Air, water, a piece of rock, a sheet of aluminium, a mirror, a wooden  board, a sheet of polythene, a CD, smoke, a sheet of plane glass, fog, an umbrella, a wall, a sheet of carbon paper, a sheet of cardboard, a sheet of cellophane, a wire mesh, moon.

Que.3. Can you think of creating a shape that would give a circular shadow if held in one way and a rectangular shadow if held in another way?

Ans: Yes, there are many things which give a circular shadow if held in one way and a rectangular shadow if held in another way. For example: a cylinder, a circular disc etc.

Que. 4. In a completely dark room, if you hold up a mirror in front of you, will you see a reflection of yourself in the mirror?

Ans: No, in a completely dark room no image will be formed because there is no light in the room so no reflection of light takes place and no image will be formed.