The speed of light depends

Options

A. a.on elasticity of the medium only
B. b.on inertia of the medium only
C. c.on elasticity as well as inertia
D. d.neither on elasticity nor on inertia

Answer

To solve the question regarding what the speed of light depends on, we can follow these steps:

### Step 1: Understand the Concept of Speed of Light
The speed of light in a vacuum is a constant value, approximately \(3 \times 10^8\) m/s. However, when light travels through different media (like air, water, glass, etc.), its speed changes.

### Step 2: Introduce the Refractive Index
The refractive index (n) of a medium is defined as the ratio of the speed of light in vacuum (c) to the speed of light in that medium (v):
\[ n = \frac{c}{v} \]
From this equation, we can see that the speed of light in a medium can be expressed as:
\[ v = \frac{c}{n} \]

### Step 3: Analyze the Factors Affecting Speed of Light
The refractive index is influenced by the properties of the medium, specifically its density and how it interacts with light. The refractive index does not directly depend on the elasticity or inertia of the medium.

### Step 4: Evaluate the Given Options
The question provides four options regarding the dependence of the speed of light:
1. Elasticity of the medium
2. Inertia of the medium
3. Both elasticity and inertia
4. Neither elasticity nor inertia

Based on our understanding, the speed of light does not depend on either elasticity or inertia directly. Instead, it depends on the refractive index, which is a property of the medium.

### Step 5: Conclusion
Thus, the correct answer is option 4: "neither elasticity nor inertia."

### Final Answer
The speed of light depends on neither elasticity nor inertia.

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