Question

Q.11. The natural solid fuel is
a) Coal (b) Coke
c) Charcoal (d) LPG
Q.12. Combustion of a substance releases heat and ___.
a) Oxygen (b) Light
c) Water (d) All of these
Q.13. Hottest zone of the candle is
a) Non luminous Zone (b) Luminous Zone
c) Dark Zone (d) Blue zone at the base of wick
Q.14. When sufficient oxygen is not available, combustion of methane
produces ______ gas and water.
a) CO2
b) Hydrogen
c) Nitrogen
d) CO
Q.15. When a cracker is ignited, a sudden reaction takes place with the
evolution of heat, light and sound. Identify the type of combustion?
a) Random Combustion
b) Rapid Combustion
c) Spontaneous Combustion
d) Explosion

Q.16. The efficiency of a fuel is expressed in terms of its ________.
a) Density (b) Calorific Value
c) Volume (d) Purity
Q.17. The SI unit of the calorific value of a fuel is :-
a) Joule (b) J/Kg
c) Kilo Joule (d) KJ/Kg
Q.18. Which of the following factors are essential to ignite a fire?
a) Fuel (b) Air (Oxygen)
c) Heat (d) All of the above
Q.19. Which of the following is the smallest microorganism?
a) Algae (b) Bacterium
c) Protozoan (d) Virus
Q.20. Fungi reproduces by
a) Fission (b) Fusion
c) seed formation (d) spore formation
Q.21. Which of the following characteristics places algae in the group of
autotrophs?
a) carrying out anaerobic respiration
(b) manufacturing their food
c) feeding on dead organisms
(d) feeding on other living organisms
Q.22. The moist bread becomes moldy after a few days when it is left in a
container with a cover. Which of the following conditions favor the growth of
the fungus?
a) absence of light (b) absence of water
c) presence of sunlight (d) presence of CO2
Q.23. Which of the following microorganisms play an important role in
maintaining the balance of nitrogen gas in the atmosphere?
a) viruses (b) bacteria
c) algae (d) protozoa
Q.24. What process takes place when yeast is added to grape juice and left for
a week?
a) decomposition (b) fermentation
c) distillation (d) oxidation

Q.25. Which of the following enzymes is secreted by bacteria that can digest
cellulose?
a) Amylase (b) Cellulase
c) Lipase (d) Protease

Answer 1

Answer:

Q.11 (a) coal

Q.12 (b) light

Q.13 (b) Luminous zone

Q.14 (b) Hydrogen.

Q.15 (b) rapid combustion

Q.16 (b) Calorific value

Q.17 (d) KJ/ Kg

Q.18 (d) All of the above

Q.19 (b) Bacterium

Q.20 (d) spore formation

Q.21 (a) carrying out the anaerobic respiration

Q.22(d) pressence of CO2