For an internal combustion engine to move a vehicle down the road ,it must convert the energy stored in the fuel into mechanical energy to drive the wheels. In your car, the distributor and battery provide this starting energy by creating an electrical "spark", which helps in combustion of fuels like gasoline. Below is the reaction depicting complete combustion of gasoline in full supply of air:
`2C_8 H_(18)(l) +25 O_(2) (g) to 16 'x' `
On the basis of evolution/absorption of energy, which of the following processes are similar to combustion of fuel?
(a) Photosynthesis in plants
(b)Respiration in the human body
(c ) Decomposition of vegetable matter
(d) Decomposition of ferrous sulphate .

Options

A. (ii) & (iii)
B. (i) & (ii)
C. (iii) & (iv)
D. (ii) & (i)

Answer

To determine which processes are similar to the combustion of fuel based on energy evolution or absorption, we need to analyze each option in the context of whether they are exothermic (release energy) or endothermic (absorb energy).

### Step-by-Step Solution:

1. **Understanding Combustion**:
- Combustion of fuel is an exothermic reaction, meaning it releases energy in the form of heat. For example, the complete combustion of octane (C₈H₁₈) with oxygen produces carbon dioxide and water, releasing energy.

2. **Analyzing Photosynthesis**:
- Photosynthesis is the process by which plants convert carbon dioxide and water into glucose and oxygen using sunlight. This process absorbs energy (endothermic), as it requires sunlight to proceed.
- **Conclusion**: Photosynthesis is not similar to combustion.

3. **Analyzing Respiration**:
- Respiration in humans is the process of breaking down glucose in the presence of oxygen to produce carbon dioxide, water, and energy (ATP). This is an exothermic reaction as it releases energy.
- **Conclusion**: Respiration is similar to combustion.

4. **Analyzing Decomposition of Vegetable Matter**:
- The decomposition of vegetable matter (composting) involves the breakdown of organic materials, which releases energy as heat. This process is also exothermic.
- **Conclusion**: Decomposition of vegetable matter is similar to combustion.

5. **Analyzing Decomposition of Ferrous Sulfate**:
- The decomposition of ferrous sulfate (FeSO₄) when heated results in the formation of iron oxide, sulfur dioxide, and sulfur trioxide. This process requires heat (endothermic) to decompose.
- **Conclusion**: Decomposition of ferrous sulfate is not similar to combustion.

### Final Answer:
Based on the analysis:
- The processes that are similar to combustion in terms of energy evolution are:
- (b) Respiration in the human body
- (c) Decomposition of vegetable matter

Thus, the correct options are **(b) and (c)**.