Four optical media W, X, Y and Z have optical densities 1.35, 1.21, 1.58 and 1.002 respectively. In which optical medium will the light travel fastest?

Options

A. W
B. X
C. Y
D. Z

Explanation

To determine in which optical medium light will travel fastest, we need to analyze the given optical densities of the media. The optical densities provided are:

- Medium W: 1.35
- Medium X: 1.21
- Medium Y: 1.58
- Medium Z: 1.002

### Step 1: Understand the relationship between optical density and speed of light
The speed of light in a medium is inversely proportional to its optical density. This means that the higher the optical density, the slower the light travels in that medium.

### Step 2: Compare the optical densities
Now, we will compare the optical densities of the four media:
- W: 1.35
- X: 1.21
- Y: 1.58
- Z: 1.002

### Step 3: Identify the medium with the lowest optical density
From the comparison, we can see that:
- Medium Z has the lowest optical density of 1.002.

### Step 4: Conclude which medium allows light to travel fastest
Since light travels fastest in the medium with the lowest optical density, we conclude that light will travel fastest in medium Z.

### Final Answer:
Light will travel fastest in medium Z.

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