What is a fuel?
A
A substance that absorbs heat
B
A substance that produces heat on combustion
D
A substance that prevents combustion
Analysis & Theory
A **fuel** is a substance that **produces heat energy when burned**.
Which of the following is a **fossil fuel**?
Analysis & Theory
**Petroleum** is a **fossil fuel**, formed from the remains of ancient organisms.
Which fuel has the **highest calorific value**?
Analysis & Theory
**Hydrogen** has the **highest calorific value** (around 150 kJ/g) among known fuels.
What is **calorific value** of a fuel?
A
Energy required to ignite fuel
B
Energy absorbed during combustion
C
Amount of heat produced per unit mass
D
Amount of fuel consumed per hour
Analysis & Theory
**Calorific value** is the **amount of heat energy produced by complete combustion of 1 gram or 1 kg** of fuel.
Which of the following is a **renewable fuel**?
Analysis & Theory
**Biogas** is a **renewable fuel** as it is produced from organic waste and is sustainable.
Which of the following is a **gaseous fuel**?
Analysis & Theory
**LPG (Liquefied Petroleum Gas)** is a **gaseous fuel** used for cooking and heating.
Which one of these fuels causes **least pollution**?
Analysis & Theory
**Hydrogen** burns cleanly, producing **only water vapor**, and causes **minimal pollution**.
Which of the following is a **liquid fuel**?
Analysis & Theory
**Petrol** is a **liquid fuel** derived from crude oil and used in vehicles.
Which characteristic is **not desirable in a good fuel**?
B
High ignition temperature
Analysis & Theory
**Good fuels** should not produce harmful gases like CO or SO₂ during combustion.
Which fuel is **commonly used in thermal power plants**?
Analysis & Theory
**Coal** is the most commonly used fuel in **thermal power plants** for generating electricity.