In 'Mesoscopic Physics', we deal with

Options

A. Phenomena at laboratory
B. Molecular phenomena
C. Nuclear phenomena
D. Few tens or hundreds of atom

Answer

To solve the question regarding what we deal with in 'Mesoscopic Physics', let's break it down step by step:

### Step 1: Understand the term 'Mesoscopic Physics'
- Mesoscopic physics is a branch of condensed matter physics that focuses on materials and systems that are intermediate in size between microscopic (atomic or molecular scale) and macroscopic (bulk material) scales.

### Step 2: Identify the size range in Mesoscopic Physics
- The term 'mesoscopic' typically refers to systems that contain a few tens to hundreds of atoms. This size range is significant because it allows for the observation of quantum effects that are not present in larger, macroscopic systems.

### Step 3: Analyze the options provided
- Option 1: Phenomena at laboratory - This is too broad and does not specifically relate to the size scale.
- Option 2: Molecular phenomena - While related, this refers to smaller scales than mesoscopic.
- Option 3: Nuclear phenomena - This is also not relevant as it pertains to even smaller scales than mesoscopic.
- Option 4: Few tens or hundreds of atoms - This accurately describes the size range dealt with in mesoscopic physics.

### Step 4: Conclusion
- Based on the analysis, the correct answer is **Option 4: Few tens or hundreds of atoms**.

### Final Answer
In 'Mesoscopic Physics', we deal with few tens or hundreds of atoms.

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