DELHI PUBLIC SCHOOL TAPI

Transcription

1 DATE: 09/03/15 DELHI PUBLIC SCHOOL TAPI CLASS VI SUMMATIVE ASSESSMENT 2 SUBJECT: SCIENCE TOTAL MARKS: (OTBA) DURATION: Reading 15 Mins. + Writing 2 Hrs. 45 Mins. + Revision 15 Mins. General Instructions Ø Read the question carefully and answer only in the answer sheets given. Ø The question paper comprises of two sections A and B. You are to attempt both the sections. Ø Section B comprises of OTBA and should be written on a new page. Ø All questions are compulsory. Ø Questions number 1 to 10 in Section A are multiple choice questions. Each question is a Section A one mark question. You are to select one most appropriate response out of the four provided to you. I. Choose the correct answer from the options given. [1 10 = 10] 1. Ten millimeter is equal to a. 1 cm b. 100 cm c. 10 m d. 10 dm 2. Shadow is formed by a. Transparent object b. Translucent object c. Opaque object d. All of these. 3. A thin coil of metal, which glows when electricity is passed through it, is called a. Switch b. Insulator c. Filament d. Bulb 4. Which of the following is attracted by the magnet? a. Glass b. Plastic c. Gold d. Iron 5. Loss of water by plants is called a. Transpiration b. Condensation c. Transportation d. Evaporation 6. Which of the following gas is found in largest quantity in air? a. Oxygen b. Carbon dioxide c. Nitrogen d. Argon 7. A non-biodegradable item a. Cannot be recycled b. Can be recycled c. Can be reused d. Can be exhaustible 8. No rain or very less rain causes

2 a. Flood b. Drought c. Soil fertile d. Soil unfertile. 9. Which gas is produced on burning of fossil fuels a. Oxygen b. Nitrogen c. Carbon dioxide d. Sulphur dioxide 10. A person who separates articles into various categories and sell for recycling a. Vegetable seller b. Kabadiwala c. Factory worker d. House-cleaner II. Fill in the blanks. [1 10 = 10] 1. Wet clothes dry up in Sun due to The motion described by a simple pendulum is motion. 3. An object which does not emit light is called A device used to break the electric circuit is known as Sailor use to know the direction. 6. The gaseous envelop surrounding the surface of the earth is called We cannot see air, but we can it. 8. Air is a Waste material should be into recyclable and non- recyclable. 10. A coloured bin is used to collect non- biodegradable wastes. III. Name the following [1 10=10] 1. The process by which water vapour change into liquid water on cooling. 2. Two natural sources of water. 3. Type of motion possessed by Earth moving around the sun in its orbit. 4. Give one example of translucent object. 5. An electric device which converts electric energy into light energy. 6. Name two poles of a magnet. 7. The gas essential for combustion and respiration. 8. The gas in presence of which photosynthesis takes place. 9. Process by which waste material is put to use again. 10. Process of converting degradable waste into compost. IV. Define the following [1 5 = 5] 1. Precipitation 2. Transparent objects 3. Insulators 4. Biodegradable waste 5. Magnetic materials

3 V. Complete the following flow chart. [5] Types of Motion Movement of smoke in air Motion In straight line To and fro from its mean position Object rotates on its own axis (a) Motion in circular orbit (e) (b) (d) (c) VI. Answer the following in brief. [2 5 = 10] 1. What type of conditions do the red worms need to survive well? 2. What do you mean by open and close circuit? 3. Sea and ocean contain plenty of water, although it cannot be used by human use? Discuss. 4. Why do animals living in the soil come out of the soil when it rains heavily? 5. List two ill-effects of plastics. VII. Answer the following in brief. [3 5 = 15] 1. What is the function of gizzard in redworms? 2. How do plants and animals help each other in the exchange of gases in the atmosphere? 3. How are clouds formed? 4. Why electrician uses rubber gloves while repairing an electric supply line? 5. Height of a person is 1.75 m. express his height in cm and mm. VIII. Draw the symbols associated with following devices [1 6 = 6] 1. Switch (ON) 2. Switch (OFF) 3. Bulb 4. Cell 5. Wire 6. Battery IX. Answer the following in detail. [5 3 = 15] 1. Water drops appear on the outer surface of a glass containing ice- cold water. Why does this happen? Define the process involved for this observation. 2. Correct the following false statements.

4 a. We should use plastics as it is cheap and can be thrown. b. We should burn plastic bags after use. c. One centimeter is equal to 100 millimeter. d. We can recycle kitchen wastes e. Tube-light is a natural luminous body. 3. Which process is shown in the following picture? Explain the process. X. Study the pictures carefully and answer the questions that follow. [2 2=4] 1. The bulb will/ will not glow in picture X because. 2. The candle will remain lighted for a long time in picture A because. Section B AIR IS ALL AROUND YOU.. Air is present everywhere on earth. Air is present as a thick blanket surrounding the surface of the earth. The layer of gases around the earth is called as atmosphere. The atmosphere is dense at the surface of the earth and becomes thinner as one moves up. Air cannot be seen but is felt when it moves. The movement of air is called breeze or wind depending on its velocity or speed. Air fills in the empty space available everywhere. The atmosphere extends about 600 kilometers (about 373 miles) above the surface of the Earth. Scientists discovered that the atmosphere is divided into layers, just like a layer cake. The names and number of layers are pictured in the diagram. As you can see, each layer varies in thickness and in temperature. These layers also differ in composition the types of gases that make up each layer. Starting from the Earth s surface (the soil) and going up, we find: the troposphere, the stratosphere, the mesosphere, the thermosphere and the exosphere.

5 Troposphere: The layer of the atmosphere we live in is called the Troposphere. Tropo is a Greek word meaning turning or change. This first layer begins at sea level and ends about 15 (about 9 miles) kilometers up. The Troposphere contains about 50% of all the air in the entire atmosphere. Because it is at the bottom, air pressure, or the weight of the air, is greatest in this layer. All the clouds we see and the changes in weather we experience occur in the Troposphere. Air temperature and air pressure are not the same all the way up through the Troposphere. As altitude increases, air temperature and air pressure decreases. Mountain climbers must dress in warmer clothes as they climb higher. To keep air pressure constant as they gain altitude, airplanes are sealed to prevent air from escaping. Stratosphere: This layer lies next to the troposphere. It extends from 15 to 50 km above the earth s surface. The Stratosphere contains a special gas called ozone, which is found in a layer called the ozone layer. This layer blocks out most of the dangerous rays from our sun. These dangerous rays cause sunburn, which can lead to skin cancer. There has been a lot of discussion about this layer over the past twenty years. Scientists have discovered that the ozone layer has gotten thinner due to pollution. Now, more harmful rays reach the Earth. To protect our skin from these rays, we must wear sun block while outside, especially in the summer when we wear less clothing. It is also wise to wear sunglasses on bright days to guard against damage to our eyes. Mesosphere: Mesosphere lies directly above the stratosphere, extending from 50 to 80 km above the earth s surface. It is very rarefied but thick enough to slow down meteors hurtling into the atmosphere, where they burn up, leaving fiery trails in the night sky. Thermosphere: The thermosphere extends from 80 km above the earth s surface to the outer space. It receives extraordinarily large amounts of energy from the sun. This makes the thermosphere very hot with temperature rising as high as thousands of degrees. It is where the space the shuttle orbits. Exosphere: The uppermost layer of the atmosphere is the exosphere. It is the layer where atmosphere merges into space. Based on the above passage, answer the following questions. 1. Mention four properties of troposphere. [4] 2. Define breeze or wind. [1] 3. What is the role of ozone layer? [2] 4. Mesosphere extends upto what height above the Earth s surface? What is its function? [3] **************************************************************