Tag: study of combustion

Questions Related to study of combustion

Which of the following can be considered as an ideal fuel?

evs how to save fuel fuels fuel and effects of burning fuel study of combustion

  1. Kerosene

  2. Petrol

  3. Biogas

  4. Wood

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Correct Option: C
Explanation:

Biogas can be considered as an ideal gas because it has an appropriate calorific value, easily processed from cow dung and other waste materials. It is environment friendly and burns smoothly without any residues. It contains negligible non-volatile materials.

What is calorific value?

evs how to save fuel fuels fuel and effects of burning fuel study of combustion

  1. Amount of heat energy produced on complete combustion of 1 Kg of fuel.

  2. Amount of heat energy produced on complete combustion of 100 Kg of fuel.

  3. Amount of heat energy produced on complete combustion of 1 g of fuel.

  4. Amount of heat energy lost on complete combustion of 1 Kg of fuel.

Show answer
Correct Option: A
Explanation:

Calorific value is the quantity of heat produced by the complete combustion of a given mass of a fuel, usually expressed in joules per kilogram.

It can be defined as the amount of heat energy produced on complete combustion of 1 Kg of fuel. 


Hence, the correct option is $A$.


_______ is a fuel made by compressing natural gas.

evs how to save fuel fuels fuel and effects of burning fuel study of combustion

  1. LPG

  2. CNG

  3. Both a and b

  4. None of above

Show answer
Correct Option: B
Explanation:

Compressed natural gas (CNG) (methane stored at high pressure) can be used in place of gasoline (petrol), Diesel fuel and propane/LPG. CNG is made by compressing natural gas (which is mainly composed of methane, CH4), to less than 1 percent of the volume it occupies at standard atmospheric pressure. 

Coke is a smokeless fuel.

evs how to save fuel fuels fuel and effects of burning fuel study of combustion

  1. True

  2. False

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Correct Option: A
Explanation:

Smokeless fuels do not produce smoke when burned. Smokeless fuels are usually solid fossil fuels, such as: anthracite, coke, and charcoal.

Choose the correct statement from the following.
A good fuel is one which:

evs how to save fuel fuels fuel and effects of burning fuel study of combustion

  1. is readily available

  2. produces a large amount of heat

  3. leaves behind many undesirable substances

  4. burns easily in air at a moderate rate

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Correct Option: A,B,D
Explanation:

A good fuel produces a huge amount of heat on burning, does not produce a lot of smoke, and is easily available.

Greater the _____ value, better is the fuel.

evs how to save fuel fuels fuel and effects of burning fuel study of combustion

  1. gold

  2. iodine

  3. calorific

  4. decane

Show answer
Correct Option: C
Explanation:

Calorific value means the energy contained in a fuel or food, determined by measuring the heat produced by complete combustion of specific quantity, expressed as $J/kg$. 

Greater the calorific value, better is the fuel.

Heats of combustion of $CH _4, C _2H _4, C _2H _6 $ are -890, -1411 and -1560 KJ/mole respectively. Which has the lowest fuel value in KJ/g?

evs how to save fuel fuels fuel and effects of burning fuel study of combustion

  1. $CH _4$

  2. $C _2H _4$

  3. $C _2H _6$

  4. All same

Show answer
Correct Option: B
Explanation:
Fuel value $CH _4=\cfrac{890}{16}$ KJ/g=555.625 KJ/g

Fuel value $C _2H _4=\cfrac{1411}{28}$ KJ/g=50.4 KJ/g

Fuel value $C _2H _6=\cfrac{1560}{30}$ KJ/g=52KJ/mole

$\therefore $ Hence lowest fuel value for $C _2H _4$