CBSE Sample Papers for Class 9 SA2 Science Solved 2016 Set 2
More Solved Sample papers For Class 9 Science
SECTION – A
1. What is Avogadro’s constant ?
2. What was Bohr’s postulate on revolution of electrons in the orbits of atom ?
3. Why do you think that a plant cell is categorised under eukaryotic cell ? Give two reasons.
4. Radius of an iron sphere is 0.21 cm. If density of iron is 7.80 gcc”1, calculate its mass.
5. A sound wave travels at a speed of 340 ms-1. If its wavelength is 1.5 cm, what is the frequency of the wave ? Will it be audible ?
6. State three features of the nuclear model of an atom put forward by Rutherford.
7. An atom contains 3 protons, 3 electrons and 4 neutrons. Find its atomic number, mass number and valency ?
8. A compound XH is formed by combination of an element ‘X’ with hydrogen. Find the valency of element ‘X’. State the formula of the compounds formed by combination of:
(a)X with nitrogen
(b)X with oxygen
9. Associate the following features with groups in which they first appeared.
(a)Vascular tissues
(b)Notochord
(c)Seeds inside fruits
10. (a) For the prevention of infectious diseases, some public health programmes of childhood immunisation are conducted in the country. Name four such diseases which are covered i under this programme.
(b) Name a disease which has been eradicated from the world, state the principle behind its eradication.
11. Given below are few situations:
(i) Geeta of Class IX was having common cold. She sits with Sarika who also develops the diseases.
(ii) Animesh of Class IX shifted to a new residence, with his family, where water purification system has not been installed yet. Fie develops cholera and dysentery.
(iii) Associate these situations with their mode of transmission and assign appropriate category to them.
12. Calculate the kinetic energy of a car of mass 500 kg moving with a velocity of 36 kmh-1. Find the kinetic energy if the velocity of the car doubles.
13. State the meaning of 1 Pascal. A boy of mass 40 kg is standing on loose sand. If the area of his feet is 0.04 m2 then calculate the pressure exerted by the boy on the sand, (g = 10 ms-2)
14. What is ‘Ultrasound’ ? Explain how defects in a metal block can detected using ultrasound.
15. (a) A household has a 100 W lamp lighted for 2 hours, two 60 W lamps lighted for 4 hours and an electric fan of 50 W working for 8 hours a day. Calculate the electric units consumed each day.
(b) What energy transformation takes place in :
(i) Dry cell (ii) Electric fan
16. Ritwick’s family received a heavy electricity bill and decided not to pay it. His friend Sujoy explained them the importance of paying all bills on time and suggested some methods to reduce the units consumed in future.
(i) Write the commercial unit of Electrical energy.
(ii) What is its relation with the SI unit of energy ?
(iii) What quality of Sujoy do you observe from his suggestions ?
(iv) List any two ways you practice at home to save electricity.
17. The number of electrons, protons and neutrons in four atoms A,B, C and D are respectively 7,7, 7 ; 6, 6, 6 ; 10, 9, 10 and 6, 6, 8. Give symbolic representation of each atoms and identify the pairs of isotope and isobar from these.
18. Give reasons:
(a)Animals of phylum platyhelminthes are called flatworms.
(b)Bryophytes are called amphibians of the plant kingdom.
(c)Fungi are called saprophytes.
(d)Bacteria and tapeworms are very different in their body design.
(e)Plants like Pinus and Deodar are called gymnosperms.
19. Justify the following statements:
(a)”Availability of proper and sufficient food would prevent from infectious diseases “.
(b)”The general ways of preventing infection mostly relate to preventing exposure”. List three points of prevention of exposure.
20.(a)Name the three bones in our middle ear, which help in amplifications of the vibrations of sound.
(b)Give the audible range of human ear.
(c)Name that part of the human ear which helps in converting pressure variations into electric signals. How brain interprets them as sound ?
21.(a)Name two forms of mechanical energy.
(b)Calculate the work required to be done to stop a car of 1500 kg moving at a speed of 54 kmh-1.
(c)A body of mass 1.5 kg is thrown vertically upwards with an initial velocity of 30 ms-1. What will be its potential energy at the end of 3 s ? (g = 10 ms-2)
SECTION – B
Q.22-Q.24. OTBA Questions of 10 marks.
SECTION – C
25.Bouncing back of sound into the same medium when it strikes any hard surface is :
(a) Refraction (b) Reflection
(c) Either (a) or (6) (d) Reverberation
26.The relationship between pressure and area is:
- It is directly proportional to square of area
- It is directly proportional to area
- It is inversely proportional to area
- It is inversely proportional to square of area
27.Which of the following will cause the change in speed of the pulse :
(i) increasing distance between two ends of slinky
(ii) decreasing number of turns in slinky
(iii) changing the material of the slinky
(iv) changing the radius of each turn of slinky
(a) (i) and (iii) (b)(ii) and (iv)
(c) (iii) and (iv) (d) (ii) and (iii)
28.Which one of the following statement is incorrect with respect to algae ?
(a)All algae are microscopic
(b)Algae are thallophytes
(c)Three groups of algae are blue-green algae, brown algae and red algae
(d)Algae manufacture food
29.A student noted down the following precautions for the experiment “To verify the law of conservation of mass in a chemical reaction”.
(i) Weighing should be done carefully.
(ii)Flask should be corked tightly.
(iii)Solutions should not get mixed before the reaction.
(iv)Mixing of two solutions must be done quickly.
The precaution which needs to be corrected is:
(a) (i) (b) (ii) (c) (iii) (d) (iv)
30. When a chemical reaction between aqueous silver nitrate and aqueous sodium chloride is carried out, white precipitates of silver chloride are formed. The above reaction is an example of:
(a) Displacement reaction
(b) Double displacement reaction
(c) Decomposition reaction
(d) Combination reaction
31. From the plants given below a dicotyledonous plant is :
(a) Wheat (b) Maize
(c) Lily (d) Hibiscus
32. Which of the following is a monocot plant ?
(a) Mustard (b) China rose
(c)Pea (d) Onion
33. What do the parts labelled A, B, C and D indicate :
(а) A – stamen, B – sepal, C – carpel, D – petal
(b) A – sepal, B – stamen, C – petal, D – carpel
(c)A – sepal, B – petal, C – stamen, D – carpel
(d)A – carpel, B – stamen, C – sepal, D – petal
34. In an experiment when an object is immersed in water, what does the volume of the displaced water indicate ? While taking the reading of the level of water in a measuring cylinder what should be the position of eye ?
35. When an object is kept on a liquid, then two forces act on it. Name the two forces and their directions.
36. Presence of feathers and hollow bones with air cavities are the adaptive features of birds. How these features are helpful to them.
Answers
SECTION – A
1. What is Avogadro’s constant ?
Ans. The Avogadro’s constant (6.022 x 1023) is defined as the number of atoms in exactly 12 gram of C- 12.
2. What was Bohr’s postulate on revolution of electrons in the orbits of atom ?
Ans. While revolving in discrete orbits the electrons do not radiate energy.
3. Why do you think that a plant cell is categorised under eukaryotic cell ? Give two reasons.
Ans. Plant Cell has
- Membrane-bound organelles.
- Has a true nucleus.
4. Radius of an iron sphere is 0.21 cm. If density of iron is 7.80 gcc”1, calculate its mass.
Ans. Radius = 0.21 cm
Volume = 4/3 it (radius)3 = 4/3 x 22/7 x 0.21 x 0.21 x 0.21 = 0.038 cc
Density = mass /volume
Mass = density x volume = 0.038 x 7.8 = 0.296 g
5. A sound wave travels at a speed of 340 ms-1. If its wavelength is 1.5 cm, what is the frequency of the wave ? Will it be audible ?
Ans.
6. State three features of the nuclear model of an atom put forward by Rutherford.
Ans. (i) There is a positively charged centre in an atom called the nucleus. Nearly, all the mass of an atom resides in the nucleus.
(ii) The electrons revolve around the nucleus in well defined orbits.
(iii) The size of the nucleus is very small as compared to the size of the atom.
7. An atom contains 3 protons, 3 electrons and 4 neutrons. Find its atomic number, mass number and valency ?
Ans. Atomic number = 3, Mass number = 3+4 = 7, Valency = 1.
8. A compound XH is formed by combination of an element ‘X’ with hydrogen. Find the valency of element ‘X’. State the formula of the compounds formed by combination of:
(a)X with nitrogen
(b)X with oxygen
Ans.
9. Associate the following features with groups in which they first appeared.
(a)Vascular tissues
(b)Notochord
(c)Seeds inside fruits
Ans. (a) Pteridophyta.
(b)Protochordata
(c)Angiosperm
10. (a) For the prevention of infectious diseases, some public health programmes of childhood immunisation are conducted in the country. Name four such diseases which are covered i under this programme.
(b) Name a disease which has been eradicated from the world, state the principle behind its eradication.
Ans. (a) Tetanus, diphtheria, whooping cough measles, polio and many others.
(b) Smallpox : Based on the principle of immunisation by vaccination.
11. Given below are few situations:
(i) Geeta of Class IX was having common cold. She sits with Sarika who also develops the diseases.
(ii) Animesh of Class IX shifted to a new residence, with his family, where water purification system has not been installed yet. Fie develops cholera and dysentery.
(iii) Associate these situations with their mode of transmission and assign appropriate category to them.
Ans. (i) Transmission by air.
(ii) Transmission by water. –
(iii) Communicable diseases.
12. Calculate the kinetic energy of a car of mass 500 kg moving with a velocity of 36 kmh-1. Find the kinetic energy if the velocity of the car doubles.
Ans. Velocity = 36 kmh-1 = 10 ms-1
K.E. = 1/2 mv2 = 1/2 x 500 x 10 x 10 = 25000 Joules
New K.E. will be four times
K.E. = 4 x 25000 = 100000 Joules.
13. State the meaning of 1 Pascal. A boy of mass 40 kg is standing on loose sand. If the area of his feet is 0.04 m2 then calculate the pressure exerted by the boy on the sand, (g = 10 ms-2)
Ans.
14. What is ‘Ultrasound’ ? Explain how defects in a metal block can detected using ultrasound.
Ans. Ultrasounds are waves having frequency greater than 20 kHz. The flaws like internal cracks etc. The metal blocks are detected by using ultrasound. It is based on the fact that internal crack or hole in the block does not allow ultrasonic waves to pass through it. To detect flaw in metallic blocks, a source of ultrasonic sound is placed in front of one face of the block and a detector on the opposite face. The ultrasonic waves are produced and made to pass through one face of block and detected on the opposite face.
(a)If the ultrasonic waves pass uninterrupted through all parts of block, then there is no defect in block.
(b)If the ultrasonic waves do not reach the opposite face, then the block has the defect (like a crack or a hole).
15. (a) A household has a 100 W lamp lighted for 2 hours, two 60 W lamps lighted for 4 hours and an electric fan of 50 W working for 8 hours a day. Calculate the electric units consumed each day.
(b) What energy transformation takes place in :
(i) Dry cell (ii) Electric fan
Ans. (a) E = P x t
= 0.2 + 0.48 + 0.4 = 1.08 units
(b) (i) Chemical to Electrical.
(ii) Electrical to Kinetic.
16. Ritwick’s family received a heavy electricity bill and decided not to pay it. His friend Sujoy explained them the importance of paying all bills on time and suggested some methods to reduce the units consumed in future.
(i) Write the commercial unit of Electrical energy.
(ii) What is its relation with the SI unit of energy ?
(iii) What quality of Sujoy do you observe from his suggestions ?
(iv) List any two ways you practice at home to save electricity.
Ans. (i) kWh or unit
(ii) 1 kWh = 3.6 x 106J
(iii) Honest; Concerned about saving resources.
(iv) (a) Switch off lights and fans when not in use.
(b)Cooking vegetables and pulses in solar cooker.
(c)Wearing an extra sweater on cold days instead of using a heating device (heater or ‘sign’).
17. The number of electrons, protons and neutrons in four atoms A,B, C and D are respectively 7,7, 7 ; 6, 6, 6 ; 10, 9, 10 and 6, 6, 8. Give symbolic representation of each atoms and identify the pairs of isotope and isobar from these.
Ans.
18. Give reasons:
(a)Animals of phylum platyhelminthes are called flatworms.
(b)Bryophytes are called amphibians of the plant kingdom.
(c)Fungi are called saprophytes.
(d)Bacteria and tapeworms are very different in their body design.
(e)Plants like Pinus and Deodar are called gymnosperms.
Ans. (a) Body is dorsiventrally flattened.
(b)Like amphibians, the bryophytes grow on land but require water to complete their life cycle.
(c)Fungi are called saprophytes because they use decaying organic material as food.
(d)Bacteria is a prokaryotic moneran whereas tapeworm is a eukaryote of kingdom animalia.
(e)Because they bear naked seeds.
19. Justify the following statements:
(a)”Availability of proper and sufficient food would prevent from infectious diseases “.
(b)”The general ways of preventing infection mostly relate to preventing exposure”. List three points of prevention of exposure.
Ans.(a)Yes, because functioning of immune system will not be good if proper and sufficient food and nourishment is not available.
(b)Yes.
(1)For air borne microbes, we can prevent exposure by providing living condition that are not overcrowded.
(2)For water borne microbes, we can prevent exposure by providing safe drinking water.
(3)For vector borne disease, we can prevent exposure by providing clean environment.
20.(a)Name the three bones in our middle ear, which help in amplifications of the vibrations of sound.
(b)Give the audible range of human ear.
(c)Name that part of the human ear which helps in converting pressure variations into electric signals. How brain interprets them as sound ?
Ans.(a)Three bones are hammer, anvil and stirrup.
(b)Audible range of human ear is 20 Hz – 20 kHz.
(c)Inner ear or cochlea.
Here, pressure variations are turned into electrical signals by cochlea. These are sent to brain via auditory nerve which interprets them as sound.
21.(a)Name two forms of mechanical energy.
(b)Calculate the work required to be done to stop a car of 1500 kg moving at a speed of 54 kmh-1.
(c)A body of mass 1.5 kg is thrown vertically upwards with an initial velocity of 30 ms-1. What will be its potential energy at the end of 3 s ? (g = 10 ms-2)
Ans.
SECTION – B
22-Q.24. OTBA Questions of 10 marks.
SECTION – C
25.Bouncing back of sound into the same medium when it strikes any hard surface is :
(a) Refraction (b) Reflection
(c) Either (a) or (6) (d) Reverberation
Ans.(b)
26.The relationship between pressure and area is:
- It is directly proportional to square of area
- It is directly proportional to area
- It is inversely proportional to area
- It is inversely proportional to square of area
Ans.(c)
27.Which of the following will cause the change in speed of the pulse :
(i) increasing distance between two ends of slinky
(ii) decreasing number of turns in slinky
(iii) changing the material of the slinky
(iv) changing the radius of each turn of slinky
(a) (i) and (iii) (b)(ii) and (iv)
(c) (iii) and (iv) (d) (ii) and (iii)
Ans.(a)
28.Which one of the following statement is incorrect with respect to algae ?
(a)All algae are microscopic
(b)Algae are thallophytes
(c)Three groups of algae are blue-green algae, brown algae and red algae
(d)Algae manufacture food
Ans.(a)
29.A student noted down the following precautions for the experiment “To verify the law of conservation of mass in a chemical reaction”.
(i) Weighing should be done carefully.
(ii)Flask should be corked tightly.
(iii)Solutions should not get mixed before the reaction.
(iv)Mixing of two solutions must be done quickly.
The precaution which needs to be corrected is:
(a) (i) (b) (ii) (c) (iii) (d) (iv)
Ans.(d)
30. When a chemical reaction between aqueous silver nitrate and aqueous sodium chloride is carried out, white precipitates of silver chloride are formed. The above reaction is an example of:
(a) Displacement reaction
(b) Double displacement reaction
(c) Decomposition reaction
(d) Combination reaction
Ans. (b)
31. From the plants given below a dicotyledonous plant is :
(a) Wheat (b) Maize
(c) Lily (d) Hibiscus
Ans. (d)
32. Which of the following is a monocot plant ?
(a) Mustard (b) China rose
(c)Pea (d) Onion
Ans. (d)
33. What do the parts labelled A, B, C and D indicate :
(а) A – stamen, B – sepal, C – carpel, D – petal
(b) A – sepal, B – stamen, C – petal, D – carpel
(c)A – sepal, B – petal, C – stamen, D – carpel
(d)A – carpel, B – stamen, C – sepal, D – petal
Ans. (a)
34. In an experiment when an object is immersed in water, what does the volume of the displaced water indicate ? While taking the reading of the level of water in a measuring cylinder what should be the position of eye ?
Ans. (i) Volume of the object.
(ii) In the same level and horizontal.
35. When an object is kept on a liquid, then two forces act on it. Name the two forces and their directions.
Ans. (i) Gravitational force Vertically downwards.
(ii) Buoyant force Vertically upwards.
36. Presence of feathers and hollow bones with air cavities are the adaptive features of birds. How these features are helpful to them.
Ans. (i) Feathers – to maintain body temperature.
(ii) Air cavities – to reduce mass of body.
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