CBSE Pathshala

[Practice Paper] LESSON-7 (Combustion and Flame)  LESSON-9(Crop Production and its Management) LESSON-20 (Pollution of water) 2 marks Questions :- Q1 What is a fuel? Give examples Q2 What are combustible materials? Q3 When we boil water in paper cup, the cup does not catch fire. Why? Q4 Define ignition temperature. What is the ignition temperature of White Phosphorus? Q5 What happens when a matchstick is striked against the matchbox? Q6 Flame of a burning candle goes off, when we blow over it strongly. Give suitable reason. Q7 Differentiate between Rapid and Spontaneous Combustion. Q8 Why does a small piece of Sodium or White Phosphorus catch fire in air? Q9 What precautions should be taken at LPG godowns or petrol pumps? Q10 If a person’s cloth catches fire, how can you put it off? Q11 What are the harmful effects of incomplete combustion? Q12 How is acid rain harmful? Q13 Define Explosive Combustion with examples. Q1

LESSON -1 (The Cell – Its structure and Functions) [Source:DAV Ballabhgarh] LESSON -2 (Microorganisms : Friends or Foes ) NOTE—Q.no.1 to 30 carry two marks each.Q.no.31 to 35 carry three marks each. Q.1 Differentiate between chloroplasts and chromoplasts. Q.2 Why were the cells remained undiscovered for a long time? Q.3 Name the unit used to express cell size. Express its value in metres. Q.4 What is the function of albumen and yolk in an egg? Q.5 What is the composition and function of cytoplasm? Q.6 Describe the structure of nucleus. Q.7 What is the importance of cilia and flagella ? Q.8 Describe the various levels of organization. Q.9 Why do plant cells have cell wall? Q.10 Classify the living organisms on the basis of the cell number. Q.11 What advantage does amoeba derive by changing shape? Q.12 A hen’s egg can be seen easily. Is it a cell or a group of cells? Give reason. Q.13 Are the cells in an elephant larger than the cells in a rat? Justify your answer. Q.14 Why do vaccum p