Which of the following fuels has the lowest calorific value ?

Options

A. kerosene
B. CNG
C. biogas
D. LPG

Answer

To determine which fuel has the lowest calorific value, we need to compare the calorific values of the given fuels. The calorific value is the amount of energy released when burning 1 kg of fuel, measured in kilojoules per kilogram (kJ/kg).

### Step-by-Step Solution:

1. **Identify the fuels and their calorific values**:
- Kerosene: 45,000 kJ/kg
- CNG (Compressed Natural Gas): 50,000 kJ/kg
- Biogas: 35,000 to 40,000 kJ/kg
- LPG (Liquefied Petroleum Gas): 55,000 kJ/kg

2. **Compare the calorific values**:
- Kerosene: 45,000 kJ/kg
- CNG: 50,000 kJ/kg
- Biogas: Average of 35,000 to 40,000 kJ/kg (we can take 37,500 kJ/kg for comparison)
- LPG: 55,000 kJ/kg

3. **Identify the lowest calorific value**:
- From the values listed, we can see that biogas has the lowest calorific value, which is around 35,000 to 40,000 kJ/kg.

4. **Conclusion**:
- Therefore, the fuel with the lowest calorific value among the options provided is **biogas**.

### Final Answer:
The fuel with the lowest calorific value is **biogas**.

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