The velocity of Electro Magnetic wave depends

A. only upon the electric properties of the medium
B. only upon the magnetic properties of the medium
C. both upon the electric and magnetic properties of the medium
D. mechanical and thermal properties of the medium:

Options

A. only upon the electric properties of the medium
B. only upon the magnetic properties of the medium
C. both upon the electric and magnetic properties of the medium
D. mechanical and thermal properties of the medium:

Answer

To solve the question regarding the dependence of the velocity of electromagnetic waves, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Concept**: The velocity of electromagnetic (EM) waves in a medium is determined by the properties of that medium. Specifically, it is influenced by both electric and magnetic properties.

2. **Velocity Expression**: The velocity \( V \) of electromagnetic waves in a medium can be expressed mathematically as:
\[ V = \frac{1}{\sqrt{\mu \epsilon}} \]
where:
- \( \mu \) is the permeability of the medium (related to its magnetic properties).
- \( \epsilon \) is the permittivity of the medium (related to its electric properties).

3. **Analyzing the Components**: From the expression \( V = \frac{1}{\sqrt{\mu \epsilon}} \):
- The presence of both \( \mu \) and \( \epsilon \) indicates that the velocity of EM waves is affected by both the electric and magnetic properties of the medium.

4. **Conclusion**: Since the velocity of electromagnetic waves depends on both the electric properties (permittivity) and the magnetic properties (permeability) of the medium, we conclude that the correct answer is:
\[ \text{C. both upon the electric and magnetic properties of the medium} \]

### Final Answer:
**C. both upon the electric and magnetic properties of the medium**

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