class 7 / science worksheet

Ch: 9: SOIL: A NATURAL RESOURCE

Fill in the Blanks

1.      _____________________is the process of breaking down of rocks into smaller particles and forming soil due to long exposure to the atmosphere.

2.      Wind, water and ___________________ are some of the weathering agents.

3.      The process of weathering takes_______________ of years for the formation of soil.

4.      Soil contains____________________ which is formed by the decomposition of dead organic matter mainly from fallen leaves or other plants.

5.      _______________________present in the soil help in breaking down dead matter and converting into humus.

6.      A vertical section of soil, from ground surface to parent rock is called _____________.

7.      The A-horizon, also known as the_____________________ provides shelter to many decomposers such as microbes and worms.

8.      The B-horizon, also known as the  ________________________ is rich in minerals due to deposits of minerals.

9.      The C- horizon or thee parent rock layer is the layer through which ___________ cannot penetrate as it consists of fragments broken down from the bed rock.

10.  The C-horizon layer is also known as the _____________________  .

True or False

1.      The main constituents of the soil are sand and clay -

2.      Particles of clayey soil are easily visible and have gritty structure -

3.      Sandy soil is usually formed from rocks such as limestone, granite and shale -

4.      Sandy soil can hold air, but its water holding capacity is very less and hence such a soil is used not used for growing crops -

5.      Fine air particles in clayey soil increase the water holding capacity of soil but cannot hold air for breathing of plant roots -

6.      Sandy soil naturally forms lumps with water and is hence used for pottery and making bricks -

7.      Loamy soil is gritty as well as smooth -

8.      Sandy soil is considered the best for farming and gardening -

9.      Percolation rate for a given soil is the time taken by water to pass through it -

10.  The ability of the soil to retain water is also called its water absorption ability -

 

Ch: 14: Electric Current and its Effects                                           

Fill in the Blanks

1.      Flow of____________________ through a conducting material is called electric current.

2.      Electric current flows through an uninterrupted path called the __________________.

3.      The three essentials for electric current to flow are ____________________ , _________________ and _________________________ .

4.      A simple electric circuit can be made by using ____________________ , __________________________ and __________________________ .

5.      If we replace the metal wire with a rubber band in electric circuit , the bulb will _____________________.

6.      In a/an _____________________ circuit, current flows uninterrupted.

7.      In a/an __________________ circuit, current does not flow.

Answer in One Word

1.      Source of electric current -

2.      Positive terminal of one cell connected to the positive terminal of the next cell -

3.      Represents a circuit with help of symbols -

4.      Several cells connected together -

5.      Used for measuring potential differences -

6.      Positive terminal of one cell connected to the negative terminal of next cell -

True or false

1.      The energy present in electric current is heat energy -

2.      The heat produced during flow of current depends on the amount of resistance offered by the wire -

3.      Tungsten offers very less resistance to current flowing through it -

4.      An electric fuse consists of a wire made up of steel -

5.      The wire present in electric fuse has a very high melting point -

 
Ch11: Transportation in Animals and Plants

Fill in the Blanks

1.      A _________________________ system is required to expel waste from the body.

2.      Food in plants is transported by _________________.

3.      The blood flows through vessels called _________________.

4.      Arteries carry _____________________ blood from _______________  to different parts of the body.

5.      ________________________ artery  carries deoxygenated blood.

6.      ______________________  helps to cool the plants.

7.      ________________________ are thin walled and superficial blood vessels.

True or False

1.      Blood is an organ -

2.      A white colored pigment called haemoglobin is present in the RCB’s -

3.      Heart is located centrally and tilted towards right -

4.      The valves between auricles and ventricles allow the blood to flow in both directions -

5.      In lungs, the blood gets rid of carbon dioxide and takes in oxygen-

Label the following diagram

CLASS 6 / WORKSHEET

CLASS 7 / worksheet on COMPARING QUANTITIES

CLASS 9 / WORKSHEET ON work and energy

CLASS 10 / EXPERIMENT 5 / REFRACTION THROUGH GLASS SLAB

EXPERIMENT – 5

To study refraction of light in rectangular glass slab

THEORY

• To understand the refraction of light through a glass slab consider the figure given below which shows the refraction of light through a rectangular glass slab.
• Here in this figure AO is the light ray travelling in air and incident on glass slab at point O.
• Now on entering the glass medium this ray bends towards the normal NN’ that is light ray AO gets refracted on entering the glass medium.
• After getting refracted this ray now travels through the glass slab and at point B it comes out of the glass slab as shown in the figure.
• Since ray OB goes from glass medium to air it again gets refracted and bends away from normal N₁N'₁ and goes in direction BC.
• Here AO is the incident ray and BC is the emergent ray and they both are parallel to each other and OB is the refracted ray.
• Emergent ray is parallel to incident ray because the extent of bending of the ray of light at the opposite parallel faces which are PQ (air-glass interface) and SR (glass-air interface) of the rectangular glass slab is equal and opposite.
• In the figure i is the angle of incidence, r is the angle of refraction and e is the angle of emergence.
• Angle of incidence and angle of emergence are equal as emergent ray and incident ray are parallel to each other.
• When a light ray is incident normally to the interface of two media then there is no bending of light ray and it goes straight through the medium.

APPARATUS:

A drawing board, rectangular glass slab, office pins, sheet of white paper, a protractor and sharply pointed pencil.

PROCEDURE:

1. Fix a sheet of white paper on a drawing board with drawing pins. Place the given glass slab nearly in the middle of the sheet.
2. Mark the boundary of the glass slab with a sharp pencil and label it as PQRS after removing the slab from its position.
3. On the line PQ mark a point E and draw a normal N1EN2 at it. Draw a line AE making angle AEN1 with the normal.The angle should neither too small nor too large (say about 40 degree).
4. Now place the glass slab again on its boundary PQRS and fix two pins A and B vertically about 10 cm apart on the line AE (say points A and B).
5. Look through the glass slab along the plane of the paper from the side SR and move your head until the images of the two pins A and B are seen clearly. Closing your one eye ,adjust the position of your head in such a way that the images of the pins A and B lie in the same straight line.
6. Fix two other pins C and D vertically in such a way that the images of the pins A and B and pins C and D, all these four, lie in the same straight line. Ensure that the feet of the pins ( not their heads ) lie in the same straight line.
7. Remove the slab and also the pins from the board and encircle the pin-pricks on the paper,with a sharp pencil.
8. Join the points D and C and produce the line DC towards the slab so that it meets the boundary line RS at the point F. Join the points e and F. Thus for the incident ray represented by line AE, the refracted ray and the emergant ray are represented by EF and FD respectively.
9. On the line RS draw a normal N1'FN2'  at point F. Now, with a protractor, measure angle AEN1, angle FEN2 and angle DFN2' labelled as angle i, angle r and angle e respectively. 
10. Now place the glass slab at some other position on the sheet of paper fixed on the board and repeat all the above steps again taking another angle of incidence.
11. Measure the angle of incidence i.e angle of refraction, angle of emergence, again.

 

 RESULT:

1) Within the experimental error, ∠i = ∠e. It implies incident ray and emergent ray are parallel to each other

2) ∠i > ∠r. it means a ray of light while passing from air to glass bends towards normal.

CLASS 7 / worksheet on CONGRUENCY OF TRIANGLES

CLASS 7 / worksheet on RATIONAL NUMBERS

CLASS 6 / MATHS / HOLIDAYS HOMEWORK

CLASS 7 / HOLIDAYS HOMEWORK

CLASS 7 / MATHEMATICS / holiday homework

ARMY PUBLIC SCHOOL, GOLCONDA

DUSHERRA BREAK HOMEWORK

CLASS 7 / MATHEMATICS

Q.1: Find sum and difference of 312.456 and 213.546

Q.2: How much is the sum of 32.33 and 33.32 is more than the sum of 21.12 and 12.21.

Q.3: The complement and supplement angle of the given angles 45˚, 79⁰, 35⁰ AND 18⁰.

Q.4: Find the reciprocal of 3/5, 9/10, 3/9, 7/4 and 9/2. Also classify them as proper, improper fractions.

Q.5: Find mean, mode and median of the data 1,1,2,4,3,2,1,2,2,4.

Q.6: Write down a pair of integers whose:                            a: Sum is – 7       b: Difference is -10

Q.7: Find:-           i) ½ of 24             ii) 2/3 of 18

Q.8: Find:-           i) 1.3 X 10            ii) 153.7 X100

Q.9: Find the mean of first five whole numbers.

Q.10: Find the median of the data: 13, 16, 12, 14, 19, 12, 14, 13, 14

Q.11: Find:          i) 0.35 ÷ 5            ii) 52.5 ÷ 10         iii) 7 ÷ 3.5

Q.12: The marks (out of 100) obtained by a group of 10 students in a science test are 85, 76, 90, 85, 39, 48, 56, 95, 81 and 75.

Find the:              a: Highest and the lowest marks obtained by the students.

                                b: Range of the marks obtained.

                                c. mean

                                d. median

Q.13.Find the values of the angles x and y in the following figure.

Q.14. In the figure given below, identify

(a) a pair of corresponding angles

(b) a pair of alternate interior angles

(c) a pair of interior angles on the same side of the transversal

Q.15.There are 6 marbles in a box with numbers 1 to 6 marked on each of them.

 (a) What is the probability of drawing a marble with number 2 ?

 (b) What is the probability of drawing a marble with number 5 ?

Q.16. The runs scored in a cricket match by 11 players is as follows:

6,15,120,49,93,80,11,10,15,8,10,15

Find the mean, median and mode of this data.

Q.17. Evaluate (a) (-30) ÷ 10        (b) (50) ÷ (-5)

Q.18. Find the product   (a) (-1) x (-225)                 (b) (-15) x ( -10) x 0

Q.19. Express the following as rupees using decimals (a) 7 paise (b) 230 paise

Q.20 . Multiply and reduce to the simplest form

Q.21 Find

Q.22 Find             (-1)x(-1)x(-1)x(-1) is equal to____________

Q.23 In the given figure

 The line l ǁ m and p is a Transversal, then find the x Values of x, y, z( Give reasons)

Q.24 Find The value of ( 3⁰ + 2⁰ ) x 5⁰

Q.25 Express 1000 as product of powers of its prime factors.

Q.26 Find the value of

 

Q.27 Draw 2 plane figures with more than one line of symmetry.

Q. 28  solve the given expression

Q.29 Write the Oder of Rotation and angle of symmetry of

(a) Square            (b) Rectangle      (c) Equilateral Triangle

Q.30 Which of the following English alphabet has reflectional symmetry about a vertical mirror?

(a) B       (b) D      (c) V       (d) E

Q.31 Find the value of angle x

Q.32 An exterior angle of a triangle is 120⁰and interior opposite angles are in ratio 7:5. Find all the three angles of a triangle.

Q.33 Find the value of    1.8 + 16.03 + 2.985

Q.34 Solve the given expression using BODMAS

Q.35 In the given figure PQ // RT. Find the value of angle x and y

Q.36 Represent the given data on double bar graph

Q.37 Weight of 73 bags of cement is 4106.25 kg. Find the weight of 100 such bags.

Q.38 There are 45 people in a building. Out of them ½ are men and 1/3 are women and rest are children. Find the number of men, women and children in the building.

Q.39 The cost of a pair of shoes is Rs.346.72. How much will it cost for 17 such pair of shoes?

Q.40 In a triangle PQR, angle P = 80⁰ and angle Q = 65⁰. Find the measure of the third angle of triangle and also find the measure of exterior angle at vertex R.

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CLASS 9 / LAB ACTIVITY 3

EXPERIMENT - 3

AIM

To observe and compare the pressure exerted by a solid iron cuboid on sand while resting on its three different faces and to calculate the pressure exerted in the three cases.

THEORY

Simply stated, weight is the force acting vertically downward. The weight of an object is the force with which it is attracted towards the earth, that is:

For an object in free fall, when gravity is the only force acting on it, the expression for weight follows Newton's Second Law.

W = F, thus:

Here ‘g’ is the Earth's gravitational field strength, equal to about 9.81 m s−2.

An object's weight depends on its environment, while its mass does not. The SI unit of weight is the same as that of force, that is, Newton (N).The force acting on an object perpendicular to the surface is called thrust. The effect of thrust depends on the area on which it acts. Thus:

The thrust on unit area is called pressure. Thus:

      

SI unit of pressure is N/m2 or Nm-2 (Newton per square metre).

In honour of scientistBlaise Pascal, the SI unit of pressure is called pascal, denoted by Pa.

MATERIAL REQUIRED

Sand tub, brick, scale

PROCEDURE

Fill ¾ ths of a tray with dry sand and level it.

• Measure the dimensions of a solid iron cuboid accurately using a scale. Mark the three faces of the cuboid as A, B and C.
• Place the solid iron cuboid by the surface A on the plane levelled sand in the tray.
• After a few minutes, remove the Iron cuboid and you will see that it has made a depression in the sand. 
• Measure the depth (depression) it has made in the sand using the scale. 
• Repeat the same procedure for the other two surfaces.  

OBSERVATIONS

Gravitational force on the environment = …….. 

1. Calculate the area occupied by each surface of the solid iron cuboid. 

• • Area occupied by surface A in the sand = .............
  • Area occupied by surface B in the sand = ............. 
  • Area occupied by surface C in the sand = ............. 

2. Calculate the pressure made by each surface of the solid iron cuboid. 
   • Pressure made by the surface A in the sand = ............. N
   • Pressure made by the surface B in the sand = ............. N
   • Pressure made by the surface C in the sand = ............. N

3. Calculate the Depression.

3. • Depression made by the surface A in the sand = ............. cm
   • Depression made by the surface B in the sand = ............. cm
   • Depression made by the surface C in the sand = ............. cm

RESULT

PRESSURE EXERTED BY THREE DIFFERENT SURFACES IS DIFFERENT ALTHOUGH THE WEIGHT IS SAME.

PRECAUTIONS

1. Dried sand must be used.
2. The tray must have significant length and width.
3. Appropriate cuboid of dimension must be used.  

ANIMATION

https://www.youtube.com/watch?v=uRMPT5oQa_4