Question

Question 28
Write True/False against the following statements and also correct the false statement.
(a) A physical process in which a substance reacts with oxygen to give off heat is called combustion
(b) Water is the best extinguisher for fires involving electrical equipment
(c) Alcohol, CNG and LPG are inflammable substances.
(d) Increased concentration of nitrogen in air is believed to cause global warming.
(e) Greater the calorific value, better is the fuel
(f) Middle zone is the hottest zone of a flame.
(g) The substances which vapourise during burning, give the flame

Answer 1

(a) False – A chemical process in which a substance reacts with oxygen to give off heat is called combustion.
(b) False – Carbon dioxide is the best extinguisher for fires involving electrical equipment.
(c) True - Alcohol, CNG and LPG are inflammable substances.
(d) False – Increased concentration of carbon dioxide in air is believed to cause global warming.
(e) True - Greater the calorific value, better is the fuel.
(f) False – outer zone is the hottest zone of a flame.
(g) True - The substances which vapourise during burning, give flame.