If we completely burn the same amount of
the following fuels, the maximum amount
of heat will be obtained on burning
) (A) Petrol
(B) Liquefied Petroleum Gas (LPG)
(C) Diesel
(D) Compressed Natural Gas (CNG)
Answers
Explanation:
diesel is the answer of this question
Have you ever noticed the difference between combustion and flame? The answer to this question is dealt with in this chapter. This lesson gives us knowledge of the substances which produce flame on burning and different zones present in the flame. We also learn about the substances that combust on burning. The various classifications of combustions are described in this lesson.
This chapter includes a topic on fire, which tells us how to act when a person has caught fire, how to act when a building catches fire and measures to extinguish the fire are described briefly. All queries related to burning, combustion, fire are focused on in this lesson.
The lowest temperature at which a combustible substance catches fire when heated in the air is called its ignition temperature of a substance.
2. Which of the two has a lower ignition temperature: petrol or kerosene?
Answer
Petrol has a lower ignition temperature.
3. Name the most common fire extinguisher.
Answer
The most common fire extinguisher is water.
4. Which is the best fire extinguisher for fires involving electrical equipment and inflammable materials like petrol?
Answer
The best fire extinguisher for fires involving electrical equipment and inflammable materials like petrol is carbon dioxide.
5. Name one substance which undergoes spontaneous combustion (or burns in air at room temperature).
Answer
White phosphorous undergoes spontaneous combustion (or burns in air at room temperature).
6. Name the unit in which the calorific value is expressed.
Answer
Calorific value is expressed in energy per unit mass of the substance. Example KJ/Kg
7. Which of the following fuels has the lowest calorific value?
Diesel, Methane, Coal, CNG, Petrol
Answer
Coal has the lowest calorific value.
8. Which of the following fuels has the highest calorific value?
Diesel, Methane, CNG, Coal, Petrol
Answer
CNG and Methane have the highest calorific value.
9. Name the term which is used to express the efficiency of a fuel.
Answer
Calorific value is used to express the efficiency of a fuel.
10. Name one solid, one liquid and one gas which burn by producing a flame.
Answer
Solid: Molten wax
Liquid: Kerosene
Gas: Liquified Petroleum Gas
11. Which of the following does not produces a flame on burning?
Camphor, Charcoal, Kerosene
Answer
Charcoal does not produce flame on burning.
12. Name one fuel which burns without producing a flame.
Answer
Charcoal burns without producing flame.
13. How many zones are there in a flame?
Answer
There are three zones in a flame. Namely, innermost, middle and outer zone.
14. Which zone of a candle flame is the hottest?