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This section includes 25 Mcqs, each offering curated multiple-choice questions to sharpen your Science knowledge and support exam preparation. Choose a topic below to get started.
1. |
Ignition temperature is |
A. | The maximum temperature at which a substance catches fire |
B. | The minimum temperature at which a substance catches fire |
C. | The temperature of burning substance |
D. | The temperature in the substance when |
Answer» C. The temperature of burning substance | |
2. |
The amount of heat energy produced on complete combustion of_____ fuel iscalled its calorific value. |
A. | 1 litre |
B. | 1 Kg |
C. | 1 milli litre |
D. | 1 gram |
Answer» C. 1 milli litre | |
3. |
A person caught fire on clothes is wrapped with blanket because |
A. | The person suddenly feels cold |
B. | To hide the burnt body parts |
C. | The person’s clothes gets burnt |
D. | To reduce air supply and put fire off |
Answer» C. The person’s clothes gets burnt | |
4. |
A chemical process in which a substance reacts with oxygen to give off heat is called |
A. | Conduction |
B. | Conjunction |
C. | Combustion |
D. | Confusion |
Answer» D. Confusion | |
5. |
Fuel may be |
A. | Solid only |
B. | Solid,Liquid or gas |
C. | Liquid only |
D. | Gas only |
Answer» C. Liquid only | |
6. |
In combustion |
A. | Both heat and light is produced |
B. | Only heat is produced |
C. | Only light is produced |
D. | All are correct |
Answer» B. Only heat is produced | |
7. |
Explosion takes place because of |
A. | Release of large amount of gas under pressure due to sudden reaction |
B. | Release of large amount of heat |
C. | Release of large amount of light |
D. | None of the above |
Answer» B. Release of large amount of heat | |
8. |
When we heat water in a paper bowl over a candle, the paper does not catch fire because |
A. | Paper is not inflamable |
B. | Paper gets wet |
C. | Due to water the ignition temperature of paper is not reached |
D. | This is not possible |
Answer» D. This is not possible | |
9. |
The substances which have very low ignition temperature and can easily catch fire with a flame are called |
A. | inflammable substances |
B. | Flaming substance |
C. | Fire proof substance |
D. | None of the above |
Answer» B. Flaming substance | |
10. |
When oil or petrol catches fire, water is not used to extinguish it because |
A. | Water covers oil and oil burns under water layer which may not be noticeable |
B. | Water is heavier than oil / petrol and so remains below the oil layer which continues to burn |
C. | Water get mixed with oil and increases fire |
D. | Water gets evaporated |
Answer» C. Water get mixed with oil and increases fire | |
11. |
What is the principle of soda fire extinguisher? |
A. | Carbon dioxide produced cuts off the supply of oxygen by covering the fire like a blanket. |
B. | Water produced cuts off the supply of oxygen by covering the fire. |
C. | Fern |
D. | Nitrogen gas produced cuts off the supply of oxygen by covering the fire. |
Answer» B. Water produced cuts off the supply of oxygen by covering the fire. | |
12. |
What is burning of a substance in the presence of air with the evolution of heat called? |
A. | Distillation |
B. | Carbonization |
C. | Weed control |
D. | Refining |
Answer» D. Refining | |
13. |
On which of these factors does the flame produced by a fuel depend upon? |
A. | Calorific value |
B. | Amount of oxygen |
C. | Dodo |
D. | All of the above |
Answer» D. All of the above | |
14. |
Inspite of the danger involved with hydrogen, it is used for some applications. Where is it used? |
A. | Rocket fuel |
B. | Oxyhydrogen flame |
C. | Material X contains fats. |
D. | All of the above |
Answer» E. | |
15. |
What does the incomplete combustion of a fuel give? |
A. | CO |
B. | \[C{{O}_{2}}\] |
C. | (c) Deficiency of R causes goitre. |
D. | Oxides of nitrogen |
Answer» B. \[C{{O}_{2}}\] | |
16. |
What is the heat produced by burning 1 g of fuel completely known as? |
A. | Heat capacity |
B. | Calorific value |
C. | X consists of starch while Y consists of protein, |
D. | Boiling point |
Answer» C. X consists of starch while Y consists of protein, | |
17. |
Which of the following represents the correct increasing order of calorific value of the given fuels? |
A. | Hydrogen < LPG < Biogas < Cow dung cake < coal |
B. | Cow dung cake < Biogas < LPG < Coal < Hydrogen |
C. | Vitamins |
D. | Hydrogen < Cow dung cake < LPG < Biogas < Coal |
Answer» D. Hydrogen < Cow dung cake < LPG < Biogas < Coal | |
18. |
If the temperature falls below its ignition temperature, then what happens to the burning substance? |
A. | It gets extinguished. |
B. | It burns brightly. |
C. | fats |
D. | It burns with smoke. |
Answer» B. It burns brightly. | |
19. |
Incomplete combustion of fossil fuels releases a gas 'X?. This gas is poisonous in nature and it bums with a blue flame. Which gas does X represent? |
A. | Ozone |
B. | Chlorine |
C. | Vitamins |
D. | Carbon monoxide |
Answer» E. | |
20. |
Geeta took four combustible substances I, II, II, and IV. She found out that the ignition temperatures of I, n, III, and IV is\[{{233}^{o}}C\], \[{{473}^{o}}C,\] \[{{210}^{o}}C,\]and \[{{170}^{o}}C,\] respectively. She heats all the substances to \[{{190}^{o}}C,\]. Among the given substances, which substance will catch fire when heat is supplied to it? |
A. | I |
B. | II |
C. | A is true but R is false. |
D. | IV |
Answer» E. | |
21. |
The head of a matchstick contains a mixture of antimony trisulphide, potassium chlorate, starch, and some glue. For combustion, it is struck against a rough surface made of powdered glass and red phosphorus. Which of the following substances will be the first to get ignited when the match is struck against a rough surface? |
A. | Antimony trisulphide |
B. | Potassium chlorate |
C. | amino acid composition |
D. | Powdered glass |
Answer» D. Powdered glass | |
22. |
Which of the following fuels is the most efficient? |
A. | Coal |
B. | Wood |
C. | \[A\to (q);B\to (p);C\to (r);D\to (s)\] |
D. | Charcoal |
Answer» D. Charcoal | |
23. |
The given table lists some substances as per their burning tendencies. Produce a flame Do not produce a flame Molten wax Kerosene oil Camphor Charcoal Which of the following substances is incorrectly categorized? |
A. | Charcoal |
B. | Camphor |
C. | 3 |
D. | Molten wax |
Answer» D. Molten wax | |
24. |
Three candles X, Y, and Z are fixed on a table. A glass chimney is placed over candle X, and is rested on wooden blocks in a manner which allows the entrance of oxygen. To candle Y, a glass chimney is placed in such a way that it is simply rested on the table. For candle Z, a similar arrangement is made along with the placement of a glass plate over the chimney. Candle _____i____ bums freely. The flame of candle _____ii_____ will flicker off giving smoke, and that of candle _____iii_____ will simply go off. The information in which alternative completes the given statements? |
A. | i-X, ii-Y, iii-Z |
B. | i-Z, ii-Y, iii-X |
C. | P because it gives more proteins and energy |
D. | i-Z, ii-X, iii-Y |
Answer» B. i-Z, ii-Y, iii-X | |
25. |
The calorific value of a fuel is 330000 kJ/kg. 0.9634 kg of the fuel is taken for combustion. The total amount of heat energy (in kJ) produced during combustion is |
A. | 317922 |
B. | 215677 |
C. | mineral |
D. | 317.922 |
Answer» B. 215677 | |