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.

Chapter 7 Enhancing a Presentation (Class 5)

Chapter 7
Enhancing a Presentation

D. Answer these questions.

1. Write the steps to apply a theme to a presentation.
Ans – To apply a theme to our presentation:
Step 1: Click on Design tab.
Step 2: Click on More button in the Themes group.
Step 3: Choose a theme from the gallery and click on it to apply the theme to all the slides

2. Which command is used to preview the selected slide transition?
Ans – Preview command is used to preview the selected slide transition.

3. Write the steps to add picture background to a presentation.
Ans – Steps to add picture background to a presentation:
Step 1: Select the slide to which we want to apply the background.
Step 2: Click on Design tab.
Step 3: Click on Format Background option in the Customize group.
Step 4: Select Picture or texture fill option.
Step 5: To insert a picture from a file, choose File and select the picture that we want to insert.

4. Name the four options by which you can change the background of a slide.
Ans – The four options in which you can fill the background of a slide — Solid fill, Gradient fill, Picture or texture fill and Pattern fill

5. What is the use of slide transition in PowerPoint?
Ans – Slide transitions are the visual movements that we see when one slide changes into another slide during a slide show.

Chapter 5 Introduction to Excel 2013 (Class 6)

Chapter 5
Introduction to Excel 2013

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

1. Excel is an spreadsheet application.
2. Collection of intersecting rows and columns is called a cell.
3. By default numbers are right aligned.
4. Name box is used to locate a specific cell on the worksheet.
5. Cell address helps to refer each cell in the worksheet.

B. Fill in the blanks using the given words.

1. Three types of data that can be entered in excel worksheet are text, number and formula.
2. The cell having a bold boundary is called active cell.
3. Name box displays the cell address of the active cell.
4. Cell address is column Letter followed by row number.
5. Sheet tab displays the name of worksheets

C. Write T for true or F for false.

1. Excel is used to create text document. FALSE
2. Two types data can be entered in an Excel workbook. FALSE
3. The active cell is bordered with a dark outline. TRUE
4. There are 16,384 rows and 1,048,576 columns in a worksheet. FALSE
5. Data entered, appears in formula bar as well as in the active cell. TRUE
6. Keyboard shortcut to select entire worksheet is Ctrl + A. TRUE

D. Answer in short.

1. What is Excel?
Ans – Excel 2013 is one of the most popular spreadsheet application.

2. What do you mean by cell address? Give suitable example.
Ans – Each cell on the worksheet has a unique address that helps to refer it in the worksheet. For example, A10 is cell address where A is the column name and 10 is the row name.

3. What are the three type of data that can be entered in Excel?
Ans – Three types of data that can be entered in an Excel worksheet are: Text, Number and Formula.  

E. Answer in detail. 

1. Differentiate between Workbook and Worksheet.
Ans – An Excel document is called a workbook which is the basic Excel file. It is a collection of multiple worksheets (spreadsheet). A worksheet is a spreadsheet made up of columns and rows.

2. Explain briefly about any three components of Excel.
Ans – Rows: Rows are represented horizontally from top to bottom in the worksheet. Rows are labelled as 1, 2, 3 and so on. There are 1,048,576 rows in a worksheet.
    Columns: Columns are represented vertically from left to right. There are total 16,384 columns in a worksheet. Columns are labelled as letters A, B, C and so on up to XFD. Name Box: It displays the cell address of the active cell.

3. How do you select range of cells?
Ans - Range of cells can be selected:
    Using mouse: To select a range of cells using mouse, point your mouse pointer to the first cell of the range and drag the left mouse button until all the required cells are selected.
    Using keyboard: To select a range of cells using keyboard, press the Shift key and move to the lower last cell of the range using Arrow keys.

4. Write steps to rename a worksheet.
Ans - To rename a worksheet:
    Step 1: Double-click the sheet name in the Sheet tab.
    Step 2: Enter new name and press Enter key.

Chapter 5 Let’s Learn Flash (Class 7)

CHAPTER 5
Let’s Learn Flash

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

1. The Stage of the Flash workspace is used to create scenes of a movie.
2. Layers are like the transparent sheets stacked one over the other containing different image.
3. Timeline consists of two components-frames and layers.
4. The number of sides in the polygon can be from 3 to 32.
5. The flash document is saved with an extension   .fla.

B. Fill in the blanks using the given words.

1. Flash animations can be used for creating games.
2. Pencil tool is used to draw freehand shapes on Flash stage.
3. There are five modes of Eraser tool.
4. Ink bottle tool is used to change the outline color, style and thickness of existing shape.
5. Paint bucket tool used to fill an object with color.

C. Match the following.
 

D. Answer in short.

Que 1 Name any two drawing tools used to create basic geometrical shapes.
Ans - Polystar Tool and Rectangle Tool are used to create basic geometrical shapes.

Que 2 Define frame and layers?
Ans – Frames: Frames are small slices of time that are combined and played back in a sequence to create animation.
    Layer: Layers are like the transparent sheets stacked one over the other each containing different images. Each layer contains its own timeline with endless frames.

Que 3 What are animations?
Ans – Animations are the special visual effects to add the illusion of motion in the still object.

E. Answer in detail. 

Que 1 What is the use of Timeline in Flash CS6?
Ans – The Timeline is used to set the sequencing and timings of various objects and other elements of a Flash movie.

Que 2 What is the use of Line and Pencil tool?
Ans – Line tool – It is used to draw lines on the stage.
          Pencil tool – It is used to draw freehand lines.
       
Que 3 How do you add text in Flash document?
Ans - To add text in Flash document:–
Step 1: Click on Text tool.
Step 2: Change the Font, Font Size, Text Color from the Properties panel.
Step 3: Click on the stage and type your text.

Que 4 How can you change the color of the Flash document?
Ans - To change the color of the Flash document-
Step 1: Click on Modify from the menu bar and choose Document option. The Document Settings dialog box will open.
Step 2: Set Background color, Stage size (width x height), etc.
Step 3: Click on OK button.

Que 5 Explain the following modes of eraser:
a. Eraser Normal            b. Erase Fills                c. Erase Lines
 
Ans – a. Erase Normal: This mode erases all the objects on the stage on which you drag the eraser.
          b. Erase Fills: This mode erases only fills with lines remaining unaffected.
          c. Erase Lines: This mode erases only lines but the fills remain unaffected.

Chapter 7 Let's Use PowerPoint 2010 (Class 4)

Chapter 7
Let's Use PowerPoint 2010

D. Answer these questions.

1. What is the use of Power Point?
Ans - PowerPoint is a presentation software used to create presentations.

2. What is the presentation?
Ans - A presentation communicates an idea or a message effectively to a large group. It displays information
along with objects such as, images, text and sound.

3. What is a slide?
Ans - A slide is like an individual page in a presentation.

4. What is a theme? Name any one theme in PowerPoint 2010.
Ans - A theme is a set of background designs, font styles, colors, and layouts. Austin theme is one of the themes PowerPoint 2010.

5. What is WordArt? How do you insert WortArt text on a slide?
Ans - WordArt is used to insert attractive text in a slide. Steps to insert WordArt text on a slide:
Step 1: Click on the Insert tab.
Step 2: Click on WordArt in the Text group. A gallery appears with different WordArt styles.
Step 3: Click the style of your choice. A WordArt text box appears on the slide  
Step 4: Type your text in the box and click outside it.

6. How will you insert a picture in a slide?
Ans - We can insert our saved pictures on the slide using Pictures command.
 Step 1: Click on Insert tab on the Ribbon.
 Step 2: Click on Picture from the Images group. The Insert Picture dialog box appears.
 Step 3: Select the picture to be inserted.
 Step 4: Click on Insert button

7. What is a Slide Show? Write the steps to view Slide Show.
Ans - Slide show means presenting all the slides one by one, on full screen. A slide show can be viewed from the beginning of the slides or from the current slide.
 Step 1: Click on Slide Show tab.
 Step 2: Click on From Beginning or From Current Slide in the Start Slide Show group.

 

 

Workbook Class 6 Science Chapter 10 Motion and Measurement of Distances

Chapter 10

Motion and Measurement of Distances

I. Answer the following questions in brief:

Q.1. What type(s) of motion(s) does a ball rolling on the ground have? 

Ans - The rolling ball on the ground shows rectilinear motion as well as rotational motion. 

Q.2. Write the similarities and differences between the motion of the earth around the sun and the wheel  of bicycle.

Ans - Similarities: The motion of the earth around the sun and the wheel of bicycle shows periodic motion.

Differences: The motion of the wheel of bicycle shows rectilinear motion which is not shown by motion at earth around the sun.

Q.3. The height of a tree is 783 cm. Express it in m and mm.

Ans - Given 783 cm

1 cm  = 1 / 100 m 783/100 = 7.83 m

1 cm = 10 mm 783 x 10 = 7830 mm

Q.4. Which measuring device would you choose to measure the girth (thickness) of a tree trunk: metre rod or measuring tape? Why?

Ans - We choose a measuring tape because it can bend around the girth of a tree trunk so it is more suitable measuring device.

Q.5. What type of motion does the string of a guitar have?

Ans - The string of a guitar have periodic motion.

Q.6. The distance between Pooja's home and Charminar is 37281 m. Express this distance in km.

Ans - 1 Km = 1000 m

37281 / 1000  = 37.281 Km

Q. 7 While measuring the length of a sheet of paper, the reading of the scale at one end is 3.8 cm and at the other end is 17.5 cm. Find the length of the sheet.

Ans - 17.5 - 3.8 = 13.7 cm

II. Given one term for each of the following:

(a) Motion in which an object repeats its motion after some time. Periodic Motion  

(b) Length of path between two places. Distance.

(c) Comparison of an unknown quantity with some known quantity. Measurement

(d) Type of motion in which the moving object remains at a constant distance from a fixed point. Circular Motion

(e) Motion in a straight line  rectilinear motion

(f) Unit of length in SI units. Metre

III. Fill in the blanks:

(a) The French created the metric system in 1790.

(b) While taking measurement, the eye must be exactly in front of the point where the measurement is to be taken.

(c) A pendulum undergoes Periodic motion.

(d) 3.278 km = 3278 m.

(e) A ball rolling on the ground undergoes rectilinear as well as rotational motion.

(f) The proper device for measuring the girth of a tree is a measuring diameter tape.

IV. State whether True or False.

(a) 1234 cm = 1.234 km (False)

(b) A footstep is a standard unit of length. (False)

(c) A measuring tape is a suitable device for measuring the length of a curved line. (True)

(d) A scale with broken ends can be used to measure the length of a line. (True)

(e) An object cannot have more than one type of a motion at a time. (False)

(f) The needle of a sewing machine undergoes periodic motion. (True)

V. Given one term for each of the following:

(a) Table   -  Periodic motion

(b) 328 m -  328000 mm

(c) Bullock Cart  - Animal Power 

(d) Sprinter  - Rectilinear motion

(e) 3.28 km  - 328000 cm

(f) Rail engine  - Steam power

VI. Choose the correct alternative:

(i) Motion of earth around the sun is an example of 

Ans (a) periodic motion

(ii) 3258 cm = 

Ans (a) 32.58 m 

(iii) In the figure given below, the proper position of the eye for taking a reading of the scale is 

 

Ans (b) B

(iv) You would measure the size of your chest using 

Ans (b) measuring tape

(v) The pendulum of a clock undergoes

Ans (c) Periodic motion

(vi) In the figure given below, the length of the line XY is 

 

Ans (c) 3.5 cm