Combustion and Flame
Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.
Conditions Necessary for Combustion
SubtopicConditions Necessary for Combustion under Combustion and Flame for Grade 8 CBSE.
Preview questions (no answers)
- 1.
In the experimental setup shown in the diagram, a combustible material is heated using a heat source, yet it does not catch fire. Based on the conditions necessary for combustion, what is the most likely reason for this?
A.The material being used is non-combustible.
B.The ignition temperature was not reached.
C.There is no supporter of combustion, such as oxygen.
D.Combustion can only occur in the presence of sunlight.
- 2.
Which of the following is an essential factor to control fire?
A.Increasing the fuel
B.Removing the heat (cooling)
C.Adding more oxygen
D.Increasing the temperature
- 3.
A substance that gives off heat and light during its reaction with oxygen is said to be:
A.Undergoing evaporation
B.Undergoing combustion
C.Undergoing condensation
D.Undergoing freezing
Download the worksheet for Combustion and Flame - Conditions Necessary for Combustion to practice offline. It includes additional chapter-level practice questions.
Types of Combustion: Rapid, Spontaneous, and Explosion
SubtopicTypes of Combustion: Rapid, Spontaneous, and Explosion under Combustion and Flame for Grade 8 CBSE.
Preview questions (no answers)
- 1.
Forest fires during very hot summers are mostly due to:
A.Rapid combustion
B.Spontaneous combustion
C.Explosion
D.Slow combustion
- 2.
What is the main difference between an explosion and rapid combustion?
A.Explosion produces sound and gas suddenly
B.Rapid combustion produces sound
C.Explosion happens slowly
D.Rapid combustion produces more gas
- 3.
Rapid combustion usually requires which of the following to start?
A.External heat or spark
B.Sub-zero temperatures
C.Absolute vacuum
D.Absence of oxygen
Download the worksheet for Combustion and Flame - Types of Combustion: Rapid, Spontaneous, and Explosion to practice offline. It includes additional chapter-level practice questions.
Zones of a Candle Flame
SubtopicZones of a Candle Flame under Combustion and Flame for Grade 8 CBSE.
Preview questions (no answers)
- 1.
In a candle flame, the outer zone represents:
A.Partial oxidation
B.Complete oxidation
C.No oxidation
D.Solidification
- 2.
Which zone shows that combustion is taking place in the presence of limited air?
A.Outer zone
B.Middle zone
C.Innermost zone
D.Wick
- 3.
The 'non-luminous' zone of a flame is the ______ part.
A.Innermost
B.Middle
C.Outer
D.Base
Download the worksheet for Combustion and Flame - Zones of a Candle Flame to practice offline. It includes additional chapter-level practice questions.
Fuel Efficiency and Calorific Value
SubtopicFuel Efficiency and Calorific Value under Combustion and Flame for Grade 8 CBSE.
Preview questions (no answers)
- 1.
Which of the following is NOT a fossil fuel?
A.Coal
B.Petroleum
C.Natural Gas
D.Biogas
- 2.
Acid rain is harmful to:
A.Crops
B.Buildings
C.Soil
D.All of the above
- 3.
Calorific value determines the _______ of a fuel.
A.Color
B.Efficiency
C.Mass
D.Temperature
Download the worksheet for Combustion and Flame - Fuel Efficiency and Calorific Value to practice offline. It includes additional chapter-level practice questions.
Harmful Effects of Burning Fuels
SubtopicHarmful Effects of Burning Fuels under Combustion and Flame for Grade 8 CBSE.
Preview questions (no answers)
- 1.
Incomplete combustion occurs when there is:
A.Excess of oxygen
B.Insufficient supply of air/oxygen
C.No fuel present
D.Low temperature
- 2.
Which of the following results from Global Warming?
A.Predictable weather cycles
B.Change in rainfall patterns
C.Growth of more glaciers
D.Increase in polar ice
- 3.
What kind of particles are responsible for causing smog in big cities during winter?
A.Water droplets only
B.Oxygen molecules
C.Smoke and dust particles
D.Nitrogen gas
Download the worksheet for Combustion and Flame - Harmful Effects of Burning Fuels to practice offline. It includes additional chapter-level practice questions.