## CBSE Sample Papers for Class 9 SA2 Science Solved 2016 Set 1

More Solved Sample papers For Class 9 Science

Q.1. State the numerical value of Avogadro Constant. Q.3. Name any two groups of microorganisms from which antibiotics can be extracted.
Q.4. Define relative density. What is the density of silver given that its relative density is 10.3 ?
Q.5.A person hears an echo from the top of a tower, 2.2 seconds after the sound is produced. How far away is the tower from the person ? Speed of the sound in air is 332 m sec-1.
Q.6.(a)  When 10 g of sulphur is burnt in 10 g of oxygen 20 g of sulphur dioxide is produced ? Find the mass of sulphur dioxide formed on burning 20 g of sulphur in 30 g of oxygen ? Justify your answer by stating the law which governs your answers.
(b) State the postulate of Dalton’s atomic theory which explains the above law.
Q.7.(Ð°) Define isotopes.
(b) List any two applications of isotopes in the field of medicine.
Q.8.Write the electronic configuration and valency of the following:
(i) Chlorine
(ii) Sodium
(iii) Silicon
Q.9.How is the criteria for deciding divisions in plant kingdom different from the criteria for deciding the sub-groups among animals ?
Q.10. What is the role of the immune system, when a disease causing microbe enters the healthy human body ?
Q.11.State any three differences between cryptogamae and phanerogamae.
Q.12.Water is falling on the blades of a turbine at the rate of 6 x 103 kg per minute. The height of the fall is 10 m. Calculate the power given to the turbine. Take g = 10 ms-2
(b) A driver speed-up his vehicle when he moves up a hill. Give reason.
Q.13.(a) A dining hall has dimensions 50 m x 15 m x 3.5 m. Calculate the mass of air in the hall.  Density of air = 1.30 kgm-3..
(b) State the unit of Relative Density.
Q.14.How does the sound produced by a vibrating object in a medium reach our ears ? Explain giving the names of main parts of ear which help in the process.
Q.15. A man has power of 90 W and mass 60 kg runs up a staircase in 40 seconds. If each step of staircase is 20 cm high, calculate the number of steps.
Q.16. During the vacations, Nitin visited his native village. He observed that for washing clothes, villagers used the water from the well. Out of curiosity he drew water from the well and observed that the bucket full of water appeared to be heavier as it came out of the water. Answer the following questions based on above information:

• Name the principle used in the above passage.
• Why does the bucket appear to be heavier in air ?
• Which values are reflected in Nitin’s behaviour ?

Q.17. (a) Write down the chemical formulae of the following compounds:
(i) Magnesium nitride (ii) Calcium nitrate (iii) Sodium nitrite
(b) Find the number of atoms present in :
(i) S02 molecule
(ii) S042  ion.
Q.18. (a) State one function each of a and b.
(a)Name the opening
(b) and state its function.
(c) How many germ layers are there and which structures are formed from them name e and f ?
(d) In which part of the body digestion takes place ?
(e) Is it colonial or solitary ? Q.19. Differentiate between the following:

• Acute disease and Chronic disease.
• Infectious disease and Non-infectious disease.
• Symptom based treatment and Microbe based treatment.
• Antibiotics and Vaccines.
• Congenital disease and Acquired disease.

Q.20. Name two forms of mechanical energy. Define them and give their SI units. Find the energy of a body of mass 35 kg moving with a velocity of 15 ms-1.

Q.21. (a) Define power. Give its SI unit.
(b) How is kWh different from kW. Find the relation between commercial and SI unit of energy.
(c) A body of mass 100 kg is lifted up by 10 m. Find :
(d) the amount of work done,
(e) potential energy of the body at that height, (g = 10 ms-2)
Q.25.For effective reflection of sound, the tubes used in the experiment should have:
(a) equal lengths around 25 to 30 cm.
(b) any length and may be unequal.
(c) equal lengths but short.
(d) no conditions on the length of the tube.
Q.26. If we perform the experiment, to observe and compare the pressure exerted by a solid cuboid on sand in vacuum, we observe that the pressure exerted by the cuboid on the sand is:
(a) same as that on the Earth’s surface
(b) less than that on the Earth’s surface
(c) greater than that on the Earth’s surface
(d) equal to zero
Q.27. While measuring time taken by pulse to move in the slinky, Gauri forgot to set the time to zero in the stop watch in which its hand was at 15 sec. At the end of his experiment the needle stops at 40 sec. The time taken by pulse to travel in the slinky was :
(a) 70 sec.             (b) 25 sec.
(c) 115 sec.             (d) 45 sec.
Q.28. Out of the following the figure which represents a moss plant body ?
29. Law of conservation of mass was proposed by the Scientist:
(a) Dalton            (b) Lavoisier   (c) Archimedes                (d) Bohr
Q.30. 28 g nitrogen combines with 6 g hydrogen to form ammonia gas. If the law of conservation is true, the mass of ammonia gas will be :
(a) 28g                                             (b)       6 g                                 (c) 22 g                                     (d) 34 g
Q.31. Rohan was uprooting some plants to clean his garden. He found that it was easy to uproot them and the stem, that he was holding was hollow. The plant could be a:
(a) Pteridophyte                                                                                                   (b)           Monocotyledonous
(c) Dicotyledonous                                                                                         (d)           Bryophyte
Q.32. In monocotyledonous plants flowers have petals that are:
(a) Four in number                (b)           Five in number
(c) Two in number                  (d)           Three or multiples of three in number
Q.33. Larva breathes through spiracles or siphons present on :
(a) 5th segment  (b) 7th segment  (c) 8th segment  (d) 3rd segment
Q.34. A spring balance used for measuring mass of the cuboid has a least count of 2 gwt. Two students using the same spring balance noted two different readings, 46 gwt and 47 gwt. Which reading is correct and why ?
Q.35.An object of volume  200 cm3 is floating on a fluid with half of its portion inside the fluid as  shown below. Find the volume and weight of the fluid displaced by the object. Q.36. Enlist any two characteristics which are present in animals which belong to phylum chordata.

SECTION – A
Q.1. State the numerical value of Avogadro Constant.
Ans. Avogadro’s constant = 6.02 2 x 1023. Q.3. Name any two groups of microorganisms from which antibiotics can be extracted.
Ans. Fungi and bacteria.
Q.4. Define relative density. What is the density of silver given that its relative density is 10.3 ?
Ans. Relative density of a substance is the ratio of its density to that of water.
Relative density = density of substance / density of water.
Relative density of silver = density of sliver/density of water.
Density of silver = relative density x density of water.
Density of silver = 10.3 x 1000kgm-3.
Density of silver = 10300 kgm-3.
Q.5.A person hears an echo from the top of a tower, 2.2 seconds after the sound is produced. How far away is the tower from the person ? Speed of the sound in air is 332 m sec-1. Q.6.(a)  When 10 g of sulphur is burnt in 10 g of oxygen 20 g of sulphur dioxide is produced ? Find the mass of sulphur dioxide formed on burning 20 g of sulphur in 30 g of oxygen ? Justify your answer by stating the law which governs your answers.
(b) State the postulate of Dalton’s atomic theory which explains the above law.
Ans.(a) According to the question sulphur and oxygen combine in the ratio of 1 : 1 by mass. 20 g of sulphur will combine only with 20 g of oxygen and 40 g of sulphur dioxide will be produced. This is in accordance with law of constant proportion which says, in a chemical substance elements are always present in definite proportion by mass.
(b) The relative number and kinds of atoms are constant in a given compound.
Q.7.(Ð°) Define isotopes.
(b) List any two applications of isotopes in the field of medicine.
Ans.(a) Isotopes : Forms of the same element having the same atomic number but different mass numbers
(b)(i)  An isotope of uranium is used as a fuel in nuclear reactors.
(ii) An isotope of cobalt is used in the treatment of goitre.
Q.8.Write the electronic configuration and valency of the following:
(i) Chlorine
(ii) Sodium
(iii) Silicon
(i) Cl – At. No. 1 7 – E.C. = 2,8,7 = (valency -1)
(ii) Na – At. No. 11 – E.C. = 2, 8, 1 = (valency +1)
(iii) Si – At. No. 14 – E.C. = 2, 8, 4 = (valency 4)
Q.9.How is the criteria for deciding divisions in plant kingdom different from the criteria for deciding the sub-groups among animals ?
Ans. (i) Criteria for deciding divisions in plants are the presence and absence of seeds and fiowers, body parts differentiation, presence or absence of specialized vascular tissues and nature of seed.
(ii) The criteria for sub-divisions among animals are the presence and absence of notochord and coelom, position of nerve cords, gill slits, body segmentation, habitat and oviparity and viviparity.
Q.10. What is the role of the immune system, when a disease causing microbe enters the healthy human body ?
Ans. When a disease causing microbe enters the healthy human body, the immune system is activated in response to infection. An active immune system recruits many cells to the affected tissues to kill off the disease-causing microbes. This recruitment process is called Inflammation. As a part of this effect there are local effects such as swelling, pain and fever.
Q.11.State any three differences between cryptogamae and phanerogamae.
Ans.Differences between Cryptogamae and Phanerogamae Q.12.Water is falling on the blades of a turbine at the rate of 6 x 103 kg per minute. The height of the fall is 10 m. Calculate the power given to the turbine. Take g = 10 ms-2
(b) A driver speed-up his vehicle when he moves up a hill. Give reason.
Ans.  m= 6000 kg
t = 60 s
h = 10 m
p = E/mgh  =mgh/t = 10000 W
(b) Work done against gravity â€”> K.E.
Q.13.(a) A dining hall has dimensions 50 m x 15 m x 3.5 m. Calculate the mass of air in the hall.  Density of air = 1.30 kgm-3..
(b) State the unit of Relative Density.
Ans. (a) Volume = 50 x 15 x 3.5 = 2625 m3
d=M/V
M =vd= 50 x 15 x 3.5 x 1.3 = 3412.5 kg
(b) (6) No units.
Q.14.How does the sound produced by a vibrating object in a medium reach our ears ? Explain giving the names of main parts of ear which help in the process.
Ans.When sound waves impinge on an ear, certain nerves which are very sensitive to pressure variations in sound waves lead to sensation of hearing. Pinna collects sounds from surroundings. It passes through auditory canal at the end of which there is eardrum that starts vibrating. These vibrations are amplified in middle ear and transmitted to inner ear where these are converted into electrical signals.
Q.15. A man has power of 90 W and mass 60 kg runs up a staircase in 40 seconds. If each step of staircase is 20 cm high, calculate the number of steps.
Ans. As                     P = Work done/Time                                                                                                   .
Also,                                                   Work done = mgh
P = mgh /t
Therefore, 60 x 10 x h/40 = 90
h = â€”3/5 m
If there are n steps then, n x 20 x 10-2  =3/5
n = 30 steps.
Q.16. During the vacations, Nitin visited his native village. He observed that for washing clothes, villagers used the water from the well. Out of curiosity he drew water from the well and observed that the bucket full of water appeared to be heavier as it came out of the water. Answer the following questions based on above information:

• Name the principle used in the above passage.
• Why does the bucket appear to be heavier in air ?
• Which values are reflected in Nitin’s behaviour ?

Ans. (a) Archimedes’ Principle.

(b) Lesser upthrust; more weight acting downwards.
(c) Scientific temperament; Inquisitive.
Q.17. (a) Write down the chemical formulae of the following compounds:
(i) Magnesium nitride (ii) Calcium nitrate (iii) Sodium nitrite
(b) Find the number of atoms present in :
(i) S02 molecule
(ii) S042  ion.
Ans. (a) (i) Mg3N2, (ii) Ca(N03)2, (iii) NaN02
(b) (i) 3                                         (ii) 5
Q.18. (a) State one function each of a and b.
(a)Name the opening
(b) and state its function.
(c) How many germ layers are there and which structures are formed from them name e and f ?
(d) In which part of the body digestion takes place ?
(e) Is it colonial or solitary ? Ans. (a) (i) Protection / defence / to paralyse prey.
(ii) Catch food.
(b) Mouth : For entry and exit of substances.
(c) Two / it is diploblastic/endoderm and ectoderm epidermis and gostradermis are formed
(d) In gastrovascular cavity/ coelenteron.
(e) Solitary.
Q.19. Differentiate between the following:

• Acute disease and Chronic disease.
• Infectious disease and Non-infectious disease.
• Symptom based treatment and Microbe based treatment.
• Antibiotics and Vaccines.

Congenital disease and Acquired disease. Q.20. Name two forms of mechanical energy. Define them and give their SI units. Find the energy of a body of mass 35 kg moving with a velocity of 15 ms-1.
Ans. K.E.: Energy by virtue of motion. SI unit-joule.

P.E.: Energy by virtue of position. SI unit-joule.
E = ?, m = 35 kg, v = 15 ms-1
E = 1/2 mv2 =1/2 x 35 x 15 x 15 = 3937.5 Joules 2 2

Q.21. (a) Define power. Give its SI unit.
(b) How is kWh different from kW. Find the relation between commercial and SI unit of energy.
(c) A body of mass 100 kg is lifted up by 10 m. Find :
(d) the amount of work done,
(e) potential energy of the body at that height, (g = 10 ms-2)
Ans. (a) Power: Rate of doing work. SI unit is Watts.
(b) kWh = Unit of Energy kW = Unit of Power
1 kWh = 1000 Wh = 1000 W x 3600 s
= 3.6 x 106 Ws = 3.6 x 106  j
(c) (i) Work done = mgh = 100 x 10 x 10
= 10000kgm2s-2 = 10000 Joules
(ii) P.E. at that height = mgh = 10000 Joules.
Q.25.For effective reflection of sound, the tubes used in the experiment should have:
(a) equal lengths around 25 to 30 cm.
(b) any length and may be unequal.
(c) equal lengths but short.
(d) no conditions on the length of the tube.
Ans. (a)
Q.26. If we perform the experiment, to observe and compare the pressure exerted by a solid cuboid on sand in vacuum, we observe that the pressure exerted by the cuboid on the sand is:
(a) same as that on the Earth’s surface
(b) less than that on the Earth’s surface
(c) greater than that on the Earth’s surface
(d) equal to zero
Ans. d
Q.27. While measuring time taken by pulse to move in the slinky, Gauri forgot to set the time to zero in the stop watch in which its hand was at 15 sec. At the end of his experiment the needle stops at 40 sec. The time taken by pulse to travel in the slinky was :
(a) 70 sec.             (b) 25 sec.
115 sec. (d) 45 sec.
Ans. (b)
Q.28. Out of the following the figure which represents a moss plant body ? 29. Law of conservation of mass was proposed by the Scientist:
(a) Dalton            (b) Lavoisier   (c) Archimedes                (d) Bohr
Ans. (b)  .
Q.30. 28 g nitrogen combines with 6 g hydrogen to form ammonia gas. If the law of conservation is true, the mass of ammonia gas will be :
(a) 28g                                             (b)       6 g                                 (c) 22 g                                     (d) 34 g
Ans. (d)
Q.31. Rohan was uprooting some plants to clean his garden. He found that it was easy to uproot them and the stem, that he was holding was hollow. The plant could be a:
(a) Pteridophyte                                                                                                   (b)           Monocotyledonous
(c) Dicotyledonous                                                                                         (d)           Bryophyte
Ans. (b)
Q.32. In monocotyledonous plants flowers have petals that are:
(a) Four in number                                                                                           (b)           Five in number
(c) Two in number                                                                                           (d)           Three or multiples of three in number
Ans. (d)
Q.33. Larva breathes through spiracles or siphons present on :
(a) 5th segment  (b) 7th segment  (c) 8th segment  (d) 3rd segment
Ans. (c)
Q.34. A spring balance used for measuring mass of the cuboid has a least count of 2 gwt. Two students using the same spring balance noted two different readings, 46 gwt and 47 gwt. Which reading is correct and why ?
Ans.    46 gwt is the accurate reading. Since least count is 2 gwt so odd reading is not possible.
Q.35.An object of volume  200 cm3 is floating on a fluid with half of its portion inside the fluid as  shown below. Find the volume and weight of the fluid displaced by the object. Ans. Volume of fluid : 100 cm3
Weight of the fluid : 100 gwt.
Q.36. Enlist any two characteristics which are present in animals which belong to phylum chordata.
Ans. Notochord at some stages of life, dorsal tubular hollow nerve cord, presence of pharangeal gills slits, post anal tail, (any two)