Electron microscope has a high resolution power . This is due to

Options

A. electromagnetic lenses
B. very low wavelength of electron beam
C. low wavelength of light source used
D. high numerical aperture of glass lenses used

Explanation

**Step-by-Step Solution:**

1. **Understanding the Electron Microscope**: The electron microscope uses a beam of electrons instead of light to visualize specimens. This is a crucial point because the type of beam used affects the resolution power.

2. **Defining Resolution Power**: Resolution power refers to the ability of a microscope to distinguish between two points as separate entities. A higher resolution power means that the microscope can distinguish points that are closer together.

3. **Relationship Between Wavelength and Resolution**: The resolution power is inversely related to the wavelength of the beam used. This means that a shorter wavelength allows for a higher resolution power. In mathematical terms, the limit of resolution (L) is directly proportional to the wavelength (λ):
\[ L \propto \lambda \]
Therefore, if the wavelength is low, the limit of resolution is also low, resulting in a higher resolution power.

4. **Evaluating the Options**:
- **Option A: Electromagnetic lenses** - While these are used in electron microscopes, they do not directly contribute to the high resolution power.
- **Option B: Very low wavelength of electron beam** - This is correct because electrons have much shorter wavelengths compared to visible light, leading to higher resolution.
- **Option C: Low wavelength of light source used** - This is incorrect as electron microscopes do not use light sources.
- **Option D: High numerical aperture of the glass lens used** - This is also incorrect because electron microscopes do not use glass lenses.

5. **Conclusion**: The correct answer is **B: very low wavelength of electron beam**, as it directly contributes to the high resolution power of the electron microscope.

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