Which of the following is not an example of bio-mass energy source ?
(a) wood
(b) gobar gas
( c) atomic energy
(d) coal.

Options

A. wood
B. gobar gas
C. nuclear energy
D. coal

Answer

To determine which of the following options is not an example of a biomass energy source, we need to understand what biomass energy is. Biomass energy is derived from organic materials and is renewable. Let's analyze each option:

1. **Wood**:
- Wood is derived from trees, which are organic materials.
- It is renewable because we can grow more trees.
- Therefore, wood is a biomass energy source.

2. **Gobar gas**:
- Gobar gas is produced from cow dung, which is also an organic material.
- It is renewable as cow dung can be continuously produced.
- Hence, gobar gas is a biomass energy source.

3. **Atomic energy**:
- Atomic energy comes from nuclear reactions, typically involving uranium or plutonium.
- It is not derived from organic materials; rather, it comes from non-renewable resources.
- Therefore, atomic energy is not a biomass energy source.

4. **Coal**:
- Coal is formed from ancient organic matter, but it takes millions of years to form.
- While it is organic, it is not considered renewable because it cannot be replenished on a human timescale.
- Thus, coal is not a biomass energy source.

Based on this analysis, the option that is not an example of a biomass energy source is **(c) atomic energy**.

### Step-by-Step Solution:
1. Define biomass energy and its characteristics (organic and renewable).
2. Analyze each option:
- Wood: Organic and renewable → Biomass energy source.
- Gobar gas: Organic and renewable → Biomass energy source.
- Atomic energy: Not organic → Not a biomass energy source.
- Coal: Organic but not renewable → Not a biomass energy source.
3. Identify the correct answer: (c) atomic energy.