Script to block copy and paste

Thursday, September 29, 2016

Science Class 8th Test From Ch. 6 – Combustion And Flame

Science Class 8th Test From Ch. 6 – Combustion And Flame
Total Marks:  30                                                                                            Time: 30 minutes
Dated: 09/10/2010
Question 1: What are combustible substances? Give two examples.                    (2 marks)
Question 2: State whether True or False.                                           (1 mark x 2 = 2marks)
(i) Fuel, air and heat are not necessary for combustion.
(ii) Stone and glass pieces are non-combustible.
Question 3: Choose the correct statement.                                                             (1 mark)
(i) If a thick piece of dry wood is kept over a burning matchstick, it catches fire.
(ii) When a paper cup containing water is heated over a candle flame, the paper does not burn.
(iii) Inflammable substances have high ignition temperature.
Question 4: Name the parts labelled (i) and (ii) in the given figure of flame. (1 mark x 2 = 2 marks)

class 8 science combusition chapter flame parts 

Question 5: Name the different types of combustion.                     (1 mark x 3 = 3 marks)
Question 6: Fill in the blanks.                                                           (1 mark x 4 = 4 marks)
(i) Candle burns with a flame, but ________ does not.
(ii) A chemical process in which a substance reacts with _______ to give off heat is called combustion.
(iii) Light is given off during combustion in the form of either ________ or ________.
Question 7: Why does not a matchstick catch fire on its own at room temperature?       (2 marks)
Question 8: How can fires involving electrical equipments be controlled? Explain your answer.                                                                                                                       (2 marks)
Question 9: Match the following.                                                     (1 mark x 4 = 4 marks)
Respiratory problem
Coal mine, forest fire
Unburnt carbon particles
Cutting of trees
Spontaneous combustion
Clean fuel
Question 10: Explain the following                                                  (2 marks x 4 = 8 marks)
(i) Characteristics of good fuel
(ii) Calorific value and its unit
(iii) Acid rain
(iv) Global warming