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1 SA2QP Total no. of printed pages: 3 SUMMATIVE ASSESSMENT 2 (March 2012) SCIENCE CLASS: VIII TIME: 2 ½ hours M. Marks: Choose the correct option. (1 X 10=10) a) The Development of foetus takes place in. i) ovary ii) oviduct iii) uterus iv) none of these b) iodine is essential for the production of the harmone. i) thyroxine ii) insuline iii) growth iv) testosterone c) Which of the following is NOT the example of non contact force. i) Gravitational force ii) Muscular force iii) Magnetic force iv) Electrostatic force d) Material on which electroplating has to be done must be. i) Negative Electrode ii) Positive Electrode iii) Neutral iv) May be Positive or Negative e) Among the following which is the safest place to take shelter during thunderstorm i) under a huge tree ii) under an umbrella iii) inside a car iv) In an open space f) Which of the following constellation is also known as The hunter. i) Great Bear ii) Orion iii) Cassiopeia iv) Leo Major g) CFC (Chlorofluorocarbons) are used in. i) refrigerator ii) AC iii) Aerosol spray iv) All the above h) Image formed by a plane mirror is. i) Virtual, behind the mirror and enlarged. ii) Virtual, behind the mirror and of the same size as the object. iii) Real at the surface of the mirror and enlarged. Iv) Real behind the mirror and of the same size as the object. 1

2 SA2QP Total no. of printed pages: 3 i) Light Year is the unit of. i) time ii) mass iii) distance iv) volume j) The metal used to give shiny appearance to objects like bicycle handlebars & wheel rims is. i) Chromium ii) Zinc iii) Copper iv) Tin. 2. Answer the following very briefly. (1 X 9=9) a) What is binary fission? b) Why are endocrine glands termed as ductless glands? c) A Blacksmith hammers a hot piece of iron while making a tool. How does the force due to hammering affect the iron piece? d) Which effect of the current allows the bulb to glow? e) Why a charged body loses its charge if we touch it with our hand? f) Name two objects other than planets which are the members of the solar system. g) Which gases are mainly responsible for acid rain? h) What is an electroscope? i) Name the system used by visually challenged people for reading. 3. Answer the following briefly. (2 X 10=20) a) What is smog? What are its harmful effects? b) How can you locate the pole star with the help of Ursa Major. c) Name the scale on which the destructive energy of Earthquakes is measured. List two states in India where earthquake are more likely to strike. d) Is it safe for the electrician to carry out electrical repairs outdoors during heavy downpour? Explain. e) Why are shoulder-bags provided with broad straps? f) It is easier to write with a ball point pen than a nib pen. Why? g) Why does the voice of boys become hoarse during puberty? h) What is metamorphosis? Name an organism that undergoes metamorphosis. 2

3 SA2QP Total no. of printed pages: 3 i) Give one example each of situations in which you push or pull to change the state of motion of objects. j) What are oviparous and viviparous animals? 4. Answer the following. (3 X 7=21) a) What are artificial satellites? What are they used for? b) In the given figure the angle between incident rays and the mirror is Find the angle of reflection by applying the law of reflection. c) How does the earthquake occur? d) A child staying in the coastal region tests the drinking water and also the sea water with his tester. He finds that the compass needle deflects more in the case of sea water. Can you explain the reason? e) What is atmospheric pressure? Why we are not crushed under it? f) Differentiate between Zygote and Foetus (3Points). g) How do lubricants reduce friction? Give an example where we deliberately reduce friction. 5. Answer the following in detail. (5 X 4=20) a) Is friction a friend or a foe? Justify your answer by giving two examples each. b) Describe the process of sex determination in human beings? c) Explain Green House Effect. How does it cause global warming? d) Draw a neat labeled diagram of human eye. Mention two ways to take care of your eyes. x x 3

4 ANSWER KEY/ MARKING SCHEME SCIENCE Class:VIII M.M Choose the correct option. (1 X 10=10) a) Ans: III)uterus b) Ans: i)thyroxine c) Ans: ii) Muscular force d) Ans: i) Negative Electrode e) Ans: iii)inside a car f) Ans: ii) Orion g) Ans: iv) All the above h) Ans: ii) Virtual, behind the mirror and of the same size as the object. i) Ans: iii) distance j) Ans: i) Chromium 2. Answer the following very briefly. (1 X 9=9) a) Ans: A type of asexual reproduction in which an animal reproduces by dividing into two individual is called Binary Fission. Amoeba reproduces by Binary Fission. b) Ans: Endocrine glands release their secretion directly into blood. c) Ans: The force due to hammering brings change in the shape of iron piece. d) Ans: The heating effect of current allows the bulb to glow. e) Ans: Human body is good conductor of electric charge. Therefore if human touch a charged body, charge from the body is transferred through human body to earth. Consequently it gets discharged. f) Ans: Asteroids, comet and meteors (Accept any two) g) Ans: Sulphur dioxide & Nitrogen dioxide h) Ans: The device which is used to test whether an object is carrying charge or not is called electroscope.

5 i) Ans: Braille System 3. Answer the following briefly. (2 X 10=20) a) Ans: A combination of smoke and fog which is usually seen in the atmosphere as thick fog like layer is known as smog. (1M). Smog causes asthma, cough and wheezing in children. (1M) b) Ans: Look at the two stars at the end of Ursa Major. Imagine a straight line passing through these stars. Extend this imaginary line forward in the north direction to about five times between the two stars. This line leads to not so bright star, called pole star. (2M) c) Ans: (1M) Richter scale (1M) * Jammu & Kashmir, Rajasthan. d) Ans: Rainwater has salts dissolved in it which makes it a very good conductor electricity. Thus it is not safe to carry out electrical repairs outdoor during heavy downpour as one may get a electric shock. (2M) e) Ans: Pressure equals to force per unit area. The larger the area, the smaller the pressure. Thus broad straps increase the area of contact so pressure on the shoulder is reduced. (2M) f) Ans: while writing with a ball pen rolling friction comes into play which is lesser than sliding friction between the surface of nib and paper. So it is easier to write with a ball point pen. (2M) g) Ans: Muscle of the growing voice box sometimes go out of control which makes the voice of boys hoarse during puberty. (2M) h) Ans: The transformation of larva into an adult through drastic change is called metamorphosis. (1M) * Frog. (1M) i) Ans: * Varied responses. (1M+1M) j) Ans: Egg laying animals are called oviparous and the animals which give birth to young ones are called viviparous. 4. Answer the following. (3 X 7=21) a) Ans: The man made satellites, launched from earth, which revolve around the earth much closer than the moon are called artificial satellites. (1M) They are used for forecasting weather, transmitting TV & radio signals. They are also used for telecommunication & remote sensing. (2M)

6 b) Ans: (3M) As the angle between the normal & mirror is 90 0 So angle of incidence = =40 0 According to law of reflection Angle of reflection = Angle of incidence. Thus r=i=40 0 c) Ans: The tectonic plates of the Earth crust are in continual motion. When they brush passed on one another, or a plate goes under another due to collision, This causes disturbance in Earth crust. These disturbances or tremors reach the Earth causing Earthquake. (3M) d) Ans: Drinking water contains salts in very low quantity, thus it conducts electricity to a very low extent. Sea water on the other hand, has a greater proportion of salts dissolved in it. So it conducts electricity more easily. As the deflection in the compass needle depends on the amount of current, it deflects more in the case of sea water. (3M) e) Ans: The pressure exerted by the air around us is known as atmospheric pressure. (1M) We are not crushed under the atmospheric pressure because pressure inside our bodies is also equal to the atmospheric pressure and cancel the pressure from outside. (2M) f) Ans: ZYGOTE FOETUS 1. It has single cell. 1. It is multi-cellular. 2. It is formed by fusion of male & female gamete 2. it is formed by repeated division of Zygote 3. Body parts cannot be identified. 3. All the body parts can be identified.

7 g) Lubricants fill in the irregularities and form a thin layer between the moving surfaces, so the surfaces do not rub against each other directly. Interlocking of irregularities is avoided to a great extent.thus friction is reduced. (2M) Eg. * Varied responses. (1M) 5. Answer the following in detail. (5 X 4=20) a) Ans: Friction is both a friend and a foe. (1M) * Varied responses. (2M+2M). b) Ans: Refer Textbook Page no. 118(4M+1M) c) Ans: Refer Textbook Page no. 242(3M+2M) d) Ans: Refer Textbook Page no. 206 (Drawing 2M+ labeling1m) * Varied responses. (2M). * Accept all correct responces. X X