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question_answer1)
Which of the following does not represent characteristic of a good fuel?
A)
It should have a high calorific value. done
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B)
Its ignition temperature should be low but well above the room temperature. done
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C)
It should have a high rate of combustion. done
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D)
It should be fairly cheap and safe to handle and transport. done
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question_answer2)
How has the use of CNG in automobiles reduced the pollution in cities?
A)
It produces less amount of sulphur dioxide and chlorine. done
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B)
It does not leave any residue or smoke after burning in the engine. done
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C)
It produces large amount of carbon dioxide. done
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D)
It is used in compressed form. done
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question_answer3)
Read the given statements and select the correct option.
Statement 1: Phosphorus burns in air at room temperature. |
Statement 2: It is an example of spontaneous combustion. |
A)
Both statements 1 and 2 are true and statement 2 is the correct explanation of statement 1. done
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B)
Both statements 1 and 2 are true but statement 2 is not the correct explanation of statement 1. done
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C)
Statement 1 is true and statement 2 is false. done
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D)
Both statements 1 and 2 are false. done
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question_answer4)
Colours of flame produced by kerosene lamp, candle and Bunsen burner are respectively
A)
Blue, yellow and yellow done
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B)
Yellow, yellow and blue done
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C)
Orange, blue and yellow done
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D)
Yellow, orange and yellow. done
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question_answer5)
Global warming leads to a rise in the sea level causing floods in the coastal areas. One of the main reasons of global warming is
A)
Combustion of fuels releases sulphur dioxide which increases the temperature done
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B)
Combustion of fuels releases carbon monoxide which decreases the temperature done
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C)
Combustion of fuels releases unburnt carbon particles which causes decrease in temperature done
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D)
Combustion of fuels releases carbon dioxide which causes increase in temperature. done
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question_answer6)
Read the given statements and select the correct options.
Statement 1: Kerosene oil and wood do not catch fire on their own at room temperature. |
Statement 2: A combustible material cannot catch fire as long as its temperature is lower than its ignition temperature. |
A)
Both statements 1 and 2 are true and statement 2 is the correct explanation of statement 1. done
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B)
Both statements 1 and 2 are true but statement 2 is not the correct explanation of statement 1. done
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C)
Statement 1 is true and statement 2 is false. done
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D)
Both statements 1 and 2 are false. done
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question_answer7)
In an experiment, 4.5 kg of a fuel was completely burnt. The heat produced was 180,000 kJ. The calorific value of the fuel is
A)
180,000 kJ done
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B)
40,000 kJ done
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C)
40,000 kJ/kg done
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D)
180,000 kJ/kg done
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question_answer8)
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. done
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B)
Water produced cuts off the supply of oxygen by covering the fire. done
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C)
Acid present in the container reacts with fire. done
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D)
Nitrogen gas produced cuts off the supply of oxygen by covering the fire. done
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question_answer9)
Which of the following reactions takes place in soda-acid type fire extinguisher?
A)
\[\text{CaC}{{\text{O}}_{3}}\xrightarrow{\Delta }CaO+C{{O}_{2}}\] done
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B)
\[2NaHC{{O}_{3}}\xrightarrow{\Delta }N{{a}_{2}}C{{O}_{3}}+{{H}_{2}}O+C{{O}_{2}}\] done
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C)
\[\begin{align} & 2NaHC{{O}_{3}}+{{H}_{2}}S{{O}_{4}}\xrightarrow{{}}N{{a}_{2}}S{{O}_{4}} \\ & +2{{H}_{2}}O+2C{{O}_{2}} \\ \end{align}\] done
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D)
\[\begin{align} & \text{CaC}{{\text{O}}_{\text{3}}}\text{+}{{\text{H}}_{\text{2}}}\text{S}{{\text{O}}_{\text{4}}}\xrightarrow{{}}\text{CaS}{{\text{O}}_{\text{4}}} \\ & \text{+}{{\text{H}}_{\text{2}}}\text{O+C}{{\text{O}}_{\text{2}}} \\ \end{align}\] done
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question_answer10)
Match column I with column II and select the correct option from the codes given below.
Column I | Column II |
P. Rusting | (i) Explosion |
Q. Burning of Paper | (ii) Spontaneous combustion |
R. Sodium | (iii) Rapid combustion |
S. Fire crackers | (iv) Slow combustion |
A)
P-(ii), Q-(iii), R-(i), S-(iv) done
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B)
P-(i), Q-(iii), R-(ii), S-(iv) done
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C)
P-(iii), Q-(ii), R-(i), S-(ii) done
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D)
P-(iv), Q-(iii), R-(ii), S-(i) done
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question_answer11)
Which of the following represents the correct increasing order of calorific value of the given fuels?
A)
Hydrogen < LPG < Biogas < Cow dung cake < coal done
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B)
Cow dung cake < Biogas < LPG < Coal < Hydrogen done
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C)
Cow dung cake < Coal < Biogas < LPG < Hydrogen done
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D)
Hydrogen < Cow dung cake < LPG < Biogas < Coal done
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question_answer12)
Liquids and gaseous fuels have more advantages over solid fuels. Some of the advantages are
(i) Calorific value of liquid and gaseous fuels is higher than the solid fuels. |
(ii) Liquids and gaseous fuels have higher ignition temperatures than the solid fuels. |
(iii) Liquids and gaseous fuels are easier to store since solid fuels occupy lot of space. |
(iv) Liquids and gaseous fuels burn completely, leaving no residue. |
The correct advantages are
A)
(i), (ii) and (iii) done
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B)
(i), (iii) and (iv) done
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C)
(ii), (iii) and (iv) done
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D)
(i), (ii) and (iv). done
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question_answer13)
A spoon is kept in contact with ice cubes for some time. Later, the same spoon was held over the flame of a small candle. The observation is shown in the figure.
What do you infer from the given figure?
|
|
A)
Spoon is an inflammable substance. done
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B)
Burning of candle is a spontaneous process. done
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C)
Carbon dioxide is a product of combustion. done
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D)
Water vapour is a product of combustion. done
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question_answer14)
Which of the following statements are true?
I. Yellow flames are ideal for heating. |
II. The substances which vaporise during burning give flames. |
III. Luminous zone contains unburnt carbon particles. |
IV. The non-luminous zone has highest temperature. |
A)
I, II and III done
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B)
I, II and IV done
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C)
II, III and IV done
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D)
I, III and IV done
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question_answer15)
Calorific values of some fuels are given:
Fuel | Calorific value (kJ/kg) |
Coal | 25000-33000 |
Diesel | 45000 |
LPG | 55000 |
CNG | 50000 |
On the basis of this data, find out the correct order of efficiency of fuels.
A)
LPG > CNG > Diesel > Coal done
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B)
Coal > Diesel > LPG > CNG done
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C)
Diesel > CNG > Coal > LPG done
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D)
CNG > LPG > Diesel > Coal done
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question_answer16)
Different zones of a candle flame are marked by the letters P, Q, R and S.
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|
Which of the following statements are correct?
(i) P is the luminous zone and is the hottest part of candle flame. |
(ii) In zone Q, there is inadequate supply of oxygen. |
(in) Zone R contains unburnt wax vapours produced by melting of wax. |
(iv) In S zone, carbon monoxide burns with a blue flame. |
A)
(i) and (ii) only done
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B)
(ii), (iii) and (iv) only done
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C)
(ii) and (iv) only done
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D)
(i), (ii) and (iii) only done
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question_answer17)
Mark the correct statements) among the following.
I. Water is a very good fire extinguisher as it cools down the fuels such as wood below its ignition temperature. |
II. Water is a very good fire extinguisher for burning oils and electrical equipment?s. |
III. Sand and soil may act as a good fire extinguisher for burning oils. |
A)
I only done
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B)
II only done
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C)
III only done
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D)
I and III only done
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question_answer18)
Different methods of extinguishing a fire involve the following :
I. Removing the combustible substance. |
II. Cooling the substance to a temperature below its ignition temperature. |
III. Cutting off the supply of air. |
Which of the following statements is correct?
A)
Method I is suitable in case of a building on fire. done
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B)
Method II involves water which works when wood or paper are on fire. done
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C)
Method III involves carbon dioxide gas which is lighter than oxygen and forms a blanket around the air. done
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D)
All of these done
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question_answer19)
Neha took a burning candle and covered it with an empty glass by putting it upside down. She observed that the candle burns for some time before it finally goes off. What is the reason for this?
A)
The candle keeps burning for some time as long as the air present in the glass is available to it and then it goes off. done
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B)
The ignition temperature of the candle becomes low due to glass cover hence it goes off. done
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C)
The candle keeps burning as long as the complete wax melts away and then goes off. done
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D)
Oxygen is produced when the candle burns. This oxygen keeps the candle burning for some time and then it goes off. done
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question_answer20)
Natural resources are classified as:
P. Exhaustible |
Q. Inexhaustible |
Some natural resources are
(i) Petrol, diesel
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(ii) Coal, petroleum
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(iii) Air, water
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(iv) Cow dung cakes, sunlight
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(v) Forests, minerals
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Which of the following represents the correct match?
A)
B)
C)
D)
None of these is a correct match. done
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