Explore topic-wise MCQs in Science.

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