TIME: – 1HR                                                                                                    F.M.:- 50

              TOPICS: - Friction,  Microorganisms: Friend and Foe                                   


Q1. Each question carries 1mark.

  1. a. Microorganisms are classified into four major groups. Name
  2. Several diseases like tuberculosis, smallpox and hepatitis can be prevented by
  3. Define Friction
  4. Friction depends on the ?
  5. Give two ways to increase friction?
  6. What is atmospheric pressure?

Q2. Each question carries 2marks.

  1. Write short notes on   A. Protozoa            B. Algae
  2. Define the process of fermentation and its
  3. Write short notes on medicinal use of
  4. Find the net force acting on an object whose mass is 2 kg, as shown

5. Explain why sliding friction is less than static

Q3. Each question carries 3marks.

  1. What are the major precautions one should follow while taking antibiotics?
  2. Explain how microbes are useful to us in our day to day
  3. Explain increasing and reducing
  4. Write and explain the effect of forces.
  5. What is fluid friction? Write the factors on which fluid friction
  6. Explain why objects moving in fluids must have special

Q4. Each question carries 5marks.

  1. What are the major group of microorganisms explain each group with their harmful and useful effects in our life?   5
  2. Write and explain types of Forces ? 3
    Find the Force in dyne acting on a body of mass 10 kg and an acceleration of 8m/s2 3
  3. Explain the reason. 2+1+1+1
    a.  Force of friction increases when two surfaces are pressed
    b. While travelling on a rickshaw, you might have experienced that if the seat cover is very smooth, you tend to slip when brakes are applied
    c. The handle of a cricket bat or a badminton racquet is usually
    d. Give examples to show that friction is both a friend and Foe?