Class 8 Combustion And Flame CBSE Questions & Answers

Class 8 · Combustion And Flame

This is Science Class 8 Combustion and Flame CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
Acid rain is occurs due to :-
  • A
    oxides of sulphur
  • B
    oxides of nitrogen
  • C
    oxides of chlorine
  • D
    both oxides of nitrogen & oxides of sulphur
    Correct
2
Low ignition temperature is the cause for :
  • A
    easy storage
  • B
    fire hazards
    Correct
  • C
    global warming
  • D
    easy transport
3
Most common fire extinguisher is :
  • A
    flame
  • B
    sand
  • C
    water
    Correct
  • D
    soil
4
Find the odd one out :
  • A
    foam fire extinguisher
  • B
    oxygen fire extinguisher
    Correct
  • C
    carbon dioxide fire extinguisher
  • D
    soda acid fire extinguisher
5
When supply of air is insufficient burning of methane will produce :
  • A
    oxygen and carbon monoxide
  • B
    water and carbon dioxide
  • C
    water and carbon monoxide
    Correct
  • D
    hydrogen and carbon dioxide
6
A foam fire extinguisher is similar in its construction to :
  • A
    all the above fire extinguishers
  • B
    soap acid fire extinguisher
  • C
    soda acid fire extinguisher
    Correct
  • D
    carbon dioxide fire extinguisher
7
All flames are :
  • A
    broader at base and pointed in middle
  • B
    broader at tip and pointed at base
  • C
    broader at base and pointed at tip
    Correct
  • D
    broader in middle and pointed at base
8
A soda acid fire extinguisher contains mixture of :
  • A
    sodium bi carbonate and hydrochloric acid
  • B
    sodium bi carbonate and sulphuric acid
    Correct
  • C
    sodium carbonate and sulphurous acid
  • D
    sodium bi carbonate and nitric acid
9
The least hot part of the flame is :
  • A
    red
  • B
    blue
  • C
    black
    Correct
  • D
    yellow
10
Combustion can be defined as a :-
  • A
    cyclic change
  • B
    all the above
  • C
    chemical change
    Correct
  • D
    physical change
11
During combustion temperature rises considerably because burning :
  • A
    not uses air
  • B
    produces light
  • C
    rapidly
    Correct
  • D
    uses oxygen
12
A better fuel is one that leaves :
  • A
    a lot of residue
  • B
    useful residue
  • C
    very little residue
    Correct
  • D
    great amount of ash
13
Combustion of a fuel will remain incomplete in the absence of sufficient :
  • A
    carbon monoxide
  • B
    carbon dioxide
  • C
    oxygen
    Correct
  • D
    hydrogen
14
The inflammable substances have :
  • A
    very high vaporising temperature
  • B
    very high ignition temperature
  • C
    very low vaporising temperature
  • D
    very low ignition temperature
    Correct
15
From middle region of flame unburnt carbon particles arise due to :
  • A
    low supply of air
    Correct
  • B
    complete combustion of wax
  • C
    high supply of air
  • D
    incomplete combustion of wax