Tag: evs

Questions Related to evs

Kerosene is mixture of?

  1. Alkanes

  2. Aromatic compounds

  3. Alcohols

  4. Aliphatic acids


Correct Option: A
Explanation:

 the major components of all kerosenes are branched and straight chain alkanes and naphthenes (cycloalkanes), which normally account for at least $70\%$ by volume

Statement: Combustion can take place at all temperatures less than an ignition temperature.


State whether the given statement is true or false.

  1. True

  2. False


Correct Option: B
Explanation:

The minimum temperature at which a substance starts to burn is called its ignition temperature. Different fuels have different ignition temperatures.  Low ignition temperature means highly inflammable. For combustion, ignition temperature should at least be achieved. Substance starts burning only at a temperature equal to ignition temperature or more than it.


Hence, the given statement is $false$

Fuel efficiency is measured as 

  1. Its calorific value

  2. Amount of heat produced by fuel per unit mass or volume

  3. $kJ/Kg$

  4. None of these


Correct Option: A,B,C
Explanation:

Fuel efficieny can be measured as the amount of heat that is required by 1kg of fuel during combustion.  It is known as calorific value of the fuel.  The unit of measuring fuel efficieny is kJ/Kg.

Which of the following has lowest ignition temperature ?

  1. LPG

  2. Petrol

  3. Coal

  4. Kerosene


Correct Option: A

Producer gas is not a good fuel because:

  1. it contains $CO$ which is poisonous

  2. it contains $CO _2$

  3. it contains $CO _2$ which does not burn

  4. it contains $N _2$ which does not burn


Correct Option: D
Explanation:

The producer gas is a mixture of nitrogen and carbon monoxide. Two thirds by volume is nitrogen and one third by volume is carbon monoxide. Carbon monoxide is combustible gas in the mixture. Nitrogen is non-combustible. producer gas is not considered as good fuel because it contains Nitrogen which does not burn.


Hence, the correct option is $\text{D}$

Which of the following is an ideal fuel?

  1. Coal

  2. LPG

  3. Petrol

  4. None of these


Correct Option: D
Explanation:

An ideal gas must possess high calorific value, must have a moderate rate of combustion and must be easily available. The calorific values of coal, petrol, LPG are quite less than an ideal gas. The molecules present in an ideal gas obeys the gas laws and follows the Newtons laws of motion.


Hence, the correct option is $\text{D}$

Which one of the following is used as 'clean fuel'?

  1. Petrol

  2. Mineral oil

  3. Methane

  4. LPG


Correct Option: D

The characteristics of a ideal fuel are:

  1. it should release more energy

  2. it should be safe

  3. it should be easily transportable

  4. all of the above


Correct Option: D
Explanation:

Ideal fuel shows the following characteristics:

  • It should be  less expensive,
  • It should be easily  available,
  • It should produce a large amount of heat,
  • It can be  transported  easily
  • It has high calorific value.
  • It should  burns easily in air at a moderate rate.

Hence option D is correct.

Ideal fuel has a __________ calorific value.

  1. low

  2. high

  3. moderate

  4. zero


Correct Option: B
Explanation:

Ideal fuel has high calorific value. This ensures that more amount of heat energy is released from the combustion of unit mass of fuel. In other words, a fuel with high calorific value is better than a fuel having low calorific value.

_____ is a better domestic fuel than wood.

  1. CNG

  2. LPG

  3. Petrol

  4. All of above


Correct Option: B
Explanation:

LPG is a better domestic fuel than wood because of several reasons. Unlike wood, LPG burns without smoke. This makes the life of housewives more comfortable and they do not have to worry about blackening of pots and pans. Moreover, use of LPG as domestic fuel also rules out the chances of getting respiratory disorders which may happen when someone uses wood as kitchen fuel. Storage and transportation of LPG is easier compared to that of wood.