DELHI PUBLIC SCHOOL, CHANDIGARH
Summative Assessment-I, Session 2014-15
Class : VIII, Subject : Science (Sample Paper)
Time : 3 hours MM : 90
Section-A (Physics)
Q1 Choose and write the correct option: (1 x 4 = 4)
(i) An image is formed in
(a) regular reflection (b) diffused reflection
(c) irregular reflection (d) none
Ans.Regular Reflection
(ii) When two plane mirrors are held at an angle of 60°, the number of images formed are
(a) 5 (b) 6
(c) 3 (d) 4
Ans.5
(iii) A liquid which splits into ions when electric current is passed through it is called
(a) conductor (b) insulator
(c) electrolyte (d) none
Ans.Electrolyte
(iv) The SI unit of pressure is
(a) kg/m3 (b) kg/m2
(c) pascal (d) Newton
Ans.Pascal
Q2. Give one word answer: (1 x 4 = 4)
(a) The bouncing back of a ray of light after striking a surface
Ans.Reflection
(b) Process of depositing a layer of desired metal on another material by mean of electricity
Ans.Electroplating
(c) Force per unit area
Ans.Pressure
(d) Pressure exerted by the atmosphere of the earth
Ans.Atmospheric Pressure
Q3. Give reasons: (2 x 2 = 4)
(a) Bleeding through nostrils occurs at high altitude
Ans.Because blood vessels exert a pressure to counter the atmospheric pressure at surfaces. When you go to mountains where atmospheric pressure decreases then blood vessels burst due to their own pressure. As nose have thin nerve linings, they burst out easily.
(b) No image is formed when diffused reflection takes place
Q4. Answer the given questions (2x2 =4)
(a) Draw a diagram to show image formation by a plane mirror
(b) Name the forces acting on a plastic bucket containing water held above the ground level in your hand.
Ans.Gravitational force
(c) Discuss why the forces acting on the bucket do not bring changes in its state of motion.
Ans.Because net force acting on the bucket is zero.
Q5. Answer the given questions (3x3=9)
(a) On what factors does effect of force depend? Give one difference between muscular force and gravitational force
Ans.The factor of a force depends on two things: 1. the amount of a force applied. The more the force applied the greater the effect.
2. the area on which the force is applied. The smaller the area the force is applied on, the greater the effect.
(b) Why is iron electroplated with tin to make cans for storing food? Name any 4 objects that are electroplated.
Ans.
(c) List 3 ways to take good care of your eyes
Ans.
Q6. (a) Draw a labelled diagram to show electroplating using copper. (2)
(b) Write the reaction showing dissociation of copper sulphate. (1)
A copper deposit forms as the positive copper ions are attracted to the negative electrode (cathode)
Cu2+(aq) + 2e– ==> Cu(s)
Ans.Copper Ions are positively charged
Section-B (Chemistry)
Q7. Choose and write the correct option: (1 x 4 = 4)
(i) Carbonisation is
(a) Slow conversion of dead vegetation into coal
(b) Deposition of soil
(c) Falling of trees
(d) None of these
Ans.Slow conversion of dead vegetation into coal
(ii) Which non-metal is a liquid at room temperature?
(a) Iodine (b) Bromine
(c) Sulphur (d) Carbon
Ans.Bromine
(iii) First synthetic fibre made entirely out of chemicals was:
(a) Acrylic (b) Nylon
(c) Rayon (d) Polyester
Ans.Nylon
(iv) Which of the following metals is the best conductor of electricity?
(a) Copper (b) Silver
(c) Aluminium (d) Gold
Ans.Gold
Q8. Give one word / name / example: (1 x 4 = 4)
a) A green substance formed on corrosion of copper
Ans.Copper Carbonate Copper Hydroxide
b) Ultimate source of energy available to us.
Ans.Sunlight
c) An important raw material for dyes and synthetic fibres
Ans.Petrochemicals
d) The black material inside a pencil
Ans.Mixture of Graphite and Lead
Q9. Answer the following: (2 x 4 = 8)
a) Cooking utensils are usually made of copper and aluminium. Explain why?
Ans.Copper and Aluminium are good conductor of heat
b) Why are blended fibres preferred over synthetic fibres?
Ans.Blended fabrics are created by combination of one or more fibres that means a new fabric is created with unique properties.The main idea of blended fabrics is to combine fibers with certain qualities with fibers of other qualities that compliment each other. Cotton and polyester are example of blend fabrics. Cotton is comfortable to wear, however, it wrinkles easy where on the other hand Polyester does not wrinkle. After combined both then results in a comfortable, yet wrinkle-resistance fabric.
c) What is displacement reaction? Give one example.
Ans.Any reaction in which more reactive element displaces less reactive element from its salt solution
for e.g copper sulphate + Ferrous-----------> Ferrous Sulphate +copper
d) Discuss any two problems related to plastic disposal
Ans.
Q10. Answer the following: (3 x 3 = 9)
a) Give any three characteristics of synthetic fibres.
Ans.
(b) Name the three products obtained on processing of coal. Give one use of each.
Ans.Coke, Coal Tar and Coal Gas
(c) What is an alloy? Give one example of alloy. How is an alloy useful over pure metal?
Ans.Alloy is an homogeneous mixture of two or more metals or metal and non metal. for e.g Steel, Brass, Bronze.
Alloy is considered better than metals because they possess properties blended properties of metals from which it was made.
Q11. (a) Identify and name the figure.
This is an Oil refinery
Define the process carried out here.
Refining of Petroleium products by using fractional distillation
b) What are the advantages of using CNG and LPG as a fuel? Give full form of CNG and LPG.
Ans The following are the advantages of CNG and LPG as a Fule
They don't leave any residue behind
They have high calorific value
They are eco friendly
They do not realease any harmful gases or fumes
CNG stands for Compressed natural gas
LPG stands for Liquified petroleum gas
Section C (Biology)
Q12. Choose the correct option: (1 x 4= 4)
(i) The cell organelle found only in plant cells is
(a) Chloroplast (b) Mitochondria
(c) Vacuole (d) Nucleus
Ans.Vacuole
(ii) The biodiversity of a region includes
(a) Plants (b) Animals
(c) Microorganisms (d) All of these
Ans.All of these
(iii) The zygote divides repeatedly to form
(a) Embryo (b) Ovum
(c) Ovary (d) Sperm
Ans.Embryo
(iv) Oil gland is also called
(a) Sebaceous gland (b) Sweat gland
(c) Endocrine (d) Salivary gland
Ans.Sebaceous Gland
Q13. Give one word / name / example: (1 x 4= 4)
(a) A cell that helps to control and coordinate the working of different parts of the body.
Ans.Nerve Cell
(b) Species of all plants of a particular area.
Ans.Flaura
(c) Female reproductive cell.
Ans.Ovume
(d) Protruding part of the throat.
Ans.Larynx
Q14. Give reason: (2 x 4 = 8)
(a) The plant cells have a cell wall outside the plasma membrane.
Ans.Plants are stationary, so they have extra protection in the form of cell wall which provides protection against various environmental conditions like rainfall, temperature wind etc.
(b) Even protected forests are not completely safe for wild animals.
(c) Layer of jelly is present around the eggs of the frog.
Ans.
(d) Pituitary gland is an endocrine gland.
Ans.It is a ductless gland as it releases hormones into the blood stream
Q15. Answer the following
(a) Observe the diagram given below:
i) Label parts x and y.
Nucelous and Cytoplasm
ii) Name the part of the human body to which these cells belong
Cheek
(b) (i) What is an ecosystem? (1+2=3)
Ans.
An ecosystem includes all of the living things (plants, animals and organisms) in a given area, interacting with each other, and also with their non-living environments (weather, earth, sun, soil, climate, atmosphere).
(ii) Define migration. Why do birds migrate?
(c) List three physical changes that take place in girls at puberty. (3)
(d) (i) Observe the diagram and answer the questions given below: (2+1+2=5)
1) Identify and name the reproductive cell.
Ans.Sperm
2) Label the part A.
Ans.Mid piece
(ii) What is the importance of reproduction in organisms?
Ans.It keeps the cycle of life continous. Reproduction is important for the survival of all living things. Without a mechanism for reproduction, life would come to an end. There are two types of reproduction to learn in elementary grades, asexual and sexual reproduction.
(iii) What is the importance of in-vitro fertilization?
Ans.
Summative Assessment-I, Session 2014-15
Class : VIII, Subject : Science (Sample Paper)
Time : 3 hours MM : 90
Section-A (Physics)
Q1 Choose and write the correct option: (1 x 4 = 4)
(i) An image is formed in
(a) regular reflection (b) diffused reflection
(c) irregular reflection (d) none
Ans.Regular Reflection
(ii) When two plane mirrors are held at an angle of 60°, the number of images formed are
(a) 5 (b) 6
(c) 3 (d) 4
Ans.5
(iii) A liquid which splits into ions when electric current is passed through it is called
(a) conductor (b) insulator
(c) electrolyte (d) none
Ans.Electrolyte
(iv) The SI unit of pressure is
(a) kg/m3 (b) kg/m2
(c) pascal (d) Newton
Ans.Pascal
Q2. Give one word answer: (1 x 4 = 4)
(a) The bouncing back of a ray of light after striking a surface
Ans.Reflection
(b) Process of depositing a layer of desired metal on another material by mean of electricity
Ans.Electroplating
(c) Force per unit area
Ans.Pressure
(d) Pressure exerted by the atmosphere of the earth
Ans.Atmospheric Pressure
Q3. Give reasons: (2 x 2 = 4)
(a) Bleeding through nostrils occurs at high altitude
Ans.Because blood vessels exert a pressure to counter the atmospheric pressure at surfaces. When you go to mountains where atmospheric pressure decreases then blood vessels burst due to their own pressure. As nose have thin nerve linings, they burst out easily.
(b) No image is formed when diffused reflection takes place
Q4. Answer the given questions (2x2 =4)
(a) Draw a diagram to show image formation by a plane mirror
(b) Name the forces acting on a plastic bucket containing water held above the ground level in your hand.
Ans.Gravitational force
(c) Discuss why the forces acting on the bucket do not bring changes in its state of motion.
Ans.Because net force acting on the bucket is zero.
Q5. Answer the given questions (3x3=9)
(a) On what factors does effect of force depend? Give one difference between muscular force and gravitational force
Ans.The factor of a force depends on two things: 1. the amount of a force applied. The more the force applied the greater the effect.
2. the area on which the force is applied. The smaller the area the force is applied on, the greater the effect.
(b) Why is iron electroplated with tin to make cans for storing food? Name any 4 objects that are electroplated.
Ans.
(c) List 3 ways to take good care of your eyes
Ans.
Q6. (a) Draw a labelled diagram to show electroplating using copper. (2)
(b) Write the reaction showing dissociation of copper sulphate. (1)
A copper deposit forms as the positive copper ions are attracted to the negative electrode (cathode)
Cu2+(aq) + 2e– ==> Cu(s)
(c) During electrolysis of copper sulphate, why do copper ions move towards negative terminal? (2)positive ion reduction by electron gain
Ans.Copper Ions are positively charged
Section-B (Chemistry)
Q7. Choose and write the correct option: (1 x 4 = 4)
(i) Carbonisation is
(a) Slow conversion of dead vegetation into coal
(b) Deposition of soil
(c) Falling of trees
(d) None of these
Ans.Slow conversion of dead vegetation into coal
(ii) Which non-metal is a liquid at room temperature?
(a) Iodine (b) Bromine
(c) Sulphur (d) Carbon
Ans.Bromine
(iii) First synthetic fibre made entirely out of chemicals was:
(a) Acrylic (b) Nylon
(c) Rayon (d) Polyester
Ans.Nylon
(iv) Which of the following metals is the best conductor of electricity?
(a) Copper (b) Silver
(c) Aluminium (d) Gold
Ans.Gold
Q8. Give one word / name / example: (1 x 4 = 4)
a) A green substance formed on corrosion of copper
Ans.Copper Carbonate Copper Hydroxide
b) Ultimate source of energy available to us.
Ans.Sunlight
c) An important raw material for dyes and synthetic fibres
Ans.Petrochemicals
d) The black material inside a pencil
Ans.Mixture of Graphite and Lead
Q9. Answer the following: (2 x 4 = 8)
a) Cooking utensils are usually made of copper and aluminium. Explain why?
Ans.Copper and Aluminium are good conductor of heat
b) Why are blended fibres preferred over synthetic fibres?
Ans.Blended fabrics are created by combination of one or more fibres that means a new fabric is created with unique properties.The main idea of blended fabrics is to combine fibers with certain qualities with fibers of other qualities that compliment each other. Cotton and polyester are example of blend fabrics. Cotton is comfortable to wear, however, it wrinkles easy where on the other hand Polyester does not wrinkle. After combined both then results in a comfortable, yet wrinkle-resistance fabric.
c) What is displacement reaction? Give one example.
Ans.Any reaction in which more reactive element displaces less reactive element from its salt solution
for e.g copper sulphate + Ferrous-----------> Ferrous Sulphate +copper
d) Discuss any two problems related to plastic disposal
Ans.
Q10. Answer the following: (3 x 3 = 9)
a) Give any three characteristics of synthetic fibres.
Ans.
Characteristic of Synthetic Fibre
- Synthetic fibres are cheaper than natural fibre.
- Synthetic fibres are stronger than natural fibre.
- Synthetic fibres are more durable than natural fibre.
- It is easy to maintain the synthetic fibres.
- It is easy to wash the synthetic fabrics.
- Synthetic fabrics are dried up in less time.
- Synthetic fibres are readily available
(b) Name the three products obtained on processing of coal. Give one use of each.
Ans.Coke, Coal Tar and Coal Gas
(c) What is an alloy? Give one example of alloy. How is an alloy useful over pure metal?
Ans.Alloy is an homogeneous mixture of two or more metals or metal and non metal. for e.g Steel, Brass, Bronze.
Alloy is considered better than metals because they possess properties blended properties of metals from which it was made.
Q11. (a) Identify and name the figure.
This is an Oil refinery
Define the process carried out here.
Refining of Petroleium products by using fractional distillation
b) What are the advantages of using CNG and LPG as a fuel? Give full form of CNG and LPG.
Ans The following are the advantages of CNG and LPG as a Fule
They don't leave any residue behind
They have high calorific value
They are eco friendly
They do not realease any harmful gases or fumes
CNG stands for Compressed natural gas
LPG stands for Liquified petroleum gas
Section C (Biology)
Q12. Choose the correct option: (1 x 4= 4)
(i) The cell organelle found only in plant cells is
(a) Chloroplast (b) Mitochondria
(c) Vacuole (d) Nucleus
Ans.Vacuole
(ii) The biodiversity of a region includes
(a) Plants (b) Animals
(c) Microorganisms (d) All of these
Ans.All of these
(iii) The zygote divides repeatedly to form
(a) Embryo (b) Ovum
(c) Ovary (d) Sperm
Ans.Embryo
(iv) Oil gland is also called
(a) Sebaceous gland (b) Sweat gland
(c) Endocrine (d) Salivary gland
Ans.Sebaceous Gland
Q13. Give one word / name / example: (1 x 4= 4)
(a) A cell that helps to control and coordinate the working of different parts of the body.
Ans.Nerve Cell
(b) Species of all plants of a particular area.
Ans.Flaura
(c) Female reproductive cell.
Ans.Ovume
(d) Protruding part of the throat.
Ans.Larynx
Q14. Give reason: (2 x 4 = 8)
(a) The plant cells have a cell wall outside the plasma membrane.
Ans.Plants are stationary, so they have extra protection in the form of cell wall which provides protection against various environmental conditions like rainfall, temperature wind etc.
(b) Even protected forests are not completely safe for wild animals.
(c) Layer of jelly is present around the eggs of the frog.
Ans.
- It prevents too many sperm from getting to the egg at the same time, because of its viscosity.
- Proteins in the jelly initiate the acrosome reaction in sperm so they are ready to fertilize the egg.
- It provides a sort of "shock absorber" to prevent injury to the egg from wave action.
(d) Pituitary gland is an endocrine gland.
Ans.It is a ductless gland as it releases hormones into the blood stream
Q15. Answer the following
(a) Observe the diagram given below:
i) Label parts x and y.
Nucelous and Cytoplasm
ii) Name the part of the human body to which these cells belong
Cheek
(b) (i) What is an ecosystem? (1+2=3)
Ans.
An ecosystem includes all of the living things (plants, animals and organisms) in a given area, interacting with each other, and also with their non-living environments (weather, earth, sun, soil, climate, atmosphere).
(ii) Define migration. Why do birds migrate?
(c) List three physical changes that take place in girls at puberty. (3)
(d) (i) Observe the diagram and answer the questions given below: (2+1+2=5)
1) Identify and name the reproductive cell.
Ans.Sperm
2) Label the part A.
Ans.Mid piece
(ii) What is the importance of reproduction in organisms?
Ans.It keeps the cycle of life continous. Reproduction is important for the survival of all living things. Without a mechanism for reproduction, life would come to an end. There are two types of reproduction to learn in elementary grades, asexual and sexual reproduction.
(iii) What is the importance of in-vitro fertilization?
Ans.
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