In which of the following media, the velocity of light is maximum?

Options

A. Water
B. Glass
C. Diamond
D. Vacuum

Explanation

To determine in which medium the velocity of light is maximum, we can analyze the speed of light in different media. Here’s a step-by-step solution:

### Step 1: Understand the Speed of Light
The speed of light in a vacuum is approximately \(3 \times 10^8\) meters per second. This is the maximum speed at which light can travel.

### Step 2: Compare Different Media
We need to compare the speed of light in the following media:
- Water
- Glass
- Diamond
- Vacuum

### Step 3: Speed of Light in Different Media
- **In Water**: The speed of light is approximately \(2.25 \times 10^8\) m/s.
- **In Glass**: The speed of light is approximately \(2.00 \times 10^8\) m/s.
- **In Diamond**: The speed of light is approximately \(1.24 \times 10^8\) m/s.
- **In Vacuum**: The speed of light is \(3 \times 10^8\) m/s.

### Step 4: Identify the Maximum Speed
From the above comparisons, we can see that the speed of light is highest in a vacuum, which is \(3 \times 10^8\) m/s. In all other media (water, glass, and diamond), the speed of light is lower than in a vacuum.

### Conclusion
Therefore, the medium in which the velocity of light is maximum is **vacuum**.

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