Fuel Efficiency

Q. Why is kerosene not used in cars?

Q. In an experiment, 4.5 kg of fuel was completely burnt. The heat produced was measured to be 180, 000 kJ. Calculate the calorific value of the fuel. ​

Q.

Name two industrial fuels that are used to give energy.

Q.

Give examples for solid fuels. What are some disadvantages of solid fuel?

Q. 3 kg of coal liberates 6000 kJ of heat on combustion. Find its calorific value.

1. 2000

Q.

How many types of fuels ? Explain them with suitable examples.

Q. Which one of the following fuels is used in vehicles?

1. Wood
2. Coal
3. Diesel
4. Charcoal

Q. Define calorific value. Mention its unit too

Q. Give two reasons why LPG is a better domestic fuel than wood. [2 marks]

Q. Define calorific value. Mention its unit too

Q. Which among the following has the highest calorific value?

1. Cowdung cake
2. Wood
3. Petrol
4. Coal

Q. Which among the following has the highest calorific value?

1. Cowdung cake
2. Wood
3. Petrol
4. Coal

Q. Which of the following will produce more heat?
1. $3kg$ of fuel X (Calorific value $=12000J/kg$)
2. $4kg$ of fuel Y (Calorific value $=10000J/kg$)

1. Fuel X
2. Fuel Y
3. Both will be equal
4. Insufficient information

Q. Question 35
What steps would you suggest for the judicious use of fossil fuels?

Q. Which among the following has the highest calorific value?

1. Cowdung cake
2. Wood
3. Petrol
4. Coal

Q. Which among P, Q, R and S would be considered as a better fuel?
$$\begin{array}{ccc}\text{Material}& \text{Calorific Value (kJ)}& \text{Weight (kg)}\\ \text{P}& \text{1000}& \text{1}\\ \text{Q}& \text{1000}& \text{2}\\ \text{R}& \text{1000}& \text{3}\\ \text{S}& \text{1000}& \text{4}\end{array}$$

1. P
2. Q
3. R
4. S

Q. Generally, an ideal fuel has a _______ calorific value.

1. zero
2. moderate
3. low
4. high

Q.

Give one word/a few words for each of the following.

Fuel used as cooking gas in the kitchen

Q. On burning completely 2.5 kg of a fuel produces 87500 kJ of heat energy. The calorific value of the fuel is –

1. 35, 000 kg/kJ
2. 35, 000 kJ/kg
3. 35, 000 J/kg
4. 35, 000 g/J

Q. Fuel efficiency is expressed in terms of ________.

1. mass
2. volume
3. weight
4. calorific value

Q. The S.I. unit of calorific value is kJ/kg.

1. True
2. False

Q. Total heat produced in combustion =

1. Calorific value + mass of substance combusted
2. Calorific value/mass of substance combusted
3. Calorific value x mass of substance combusted
4. None of these

Q. Quality that is not suitable for a fuel is ________ .

1. high calorific value with ignition temperature that is well above the normal room temperature
2. low rate of evaporation at room temperature
3. carbon particles are expelled with smoke
4. low content of non-combustibles

Q. Which among the following has the highest calorific value?

1. Cowdung cake
2. Wood
3. Petrol
4. Coal

Q. Calorific value is the amount of heat liberated during the combustion of 1 kg of a substance.

1. False
2. True

Q.

"A fuel has calorific value of 25, 000 kJ/kg."
Which among the following options does the above statement implies to?

1. 1 kg of fuel will take in 25, 000 kJ of energy on complete combustion.
2. 1 kg of fuel will release 1, 00, 000 kJ of energy on complete combustion.
3. 4 kg of fuel will release 1, 00, 000 kJ of energy on complete combustion.
4. 4 kg of fuel will take in 1, 00, 000 kJ of energy on complete combustion.

Q. Which of the following is a unit to express calorific value?

1. kJ
2. J/m
3. kJ/kg
4. kJ/metre