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प्रश्न
Complete the crossword with the help of the clues.
Across
1. Non-metal which catches fire if exposed to air. (10)
3. The lowest temperature at which a substance catches fire is called its ______ temperature. (8)
5. The most common fire extinguisher. (5)
Down
2. A chemical process in which a substance reacts with oxygen to give off heat. (10)
4. Petrol is used as a ______ in automobiles. (4)
6. It is as hard as stone and black in colour. (4)
उत्तर
Across
1. Phosphorus
3. Ignition
5. Water
Down
2. Combustion
4. Fuel
6. Coal
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संबंधित प्रश्न
What is ignition temperature?
A ______ process in which a substance reacts with ______ to give off heat is called combustion.
Some words (underlined) in the following sentence is jumbled up. Write them in their correct form.
Slaags is a non-combustible material.
Fill in the blanks using the words given in the box.
| ignition | petrol | combustion | calorific value | combustible | combustible |
A chemical process in which a substance reacts with oxygen to give off heat is called ______.
People usually keep angithi/burning coal in their closed rooms during winter season. Why is it advised to keep the door open?
Write True/False against the following statement and also correct the false statement.
Increased concentration of nitrogen in air is believed to cause global warming.
Which of the following conditions is not necessary for combustion?
Complete combustion of the fuel takes place and the colour of the flame is yellow and is the hottest part of the flame.
Complete the oxidation reaction.
CH4+2O2 → ______+______+Heat energy.
Fill in the blanks using the word given in the box.
| ignition | petrol | combustion | calorific value | combustible | combustible |
Wood, paper, CNG are ______ substances.
