Light when travels from one medium to another refracts because of .........

Options

A. difference in refractive index
B. difference in velocities
C. difference in wavelengths
D. all of the above

Explanation

To answer the question "Light when travels from one medium to another refracts because of .........", we can follow these steps:

### Step 1: Understand Refraction
Refraction is the bending of light as it passes from one medium to another. This bending occurs due to a change in the speed of light in different media.

**Hint:** Remember that light travels at different speeds in different materials.

### Step 2: Identify the Factors Affecting Refraction
When light travels from one medium to another, several factors can cause it to refract:
1. **Difference in Refractive Index**: Each medium has a property called the refractive index, which is a measure of how much the speed of light is reduced inside that medium.
2. **Difference in Velocities**: The speed of light changes when it enters a different medium, which directly affects how much the light bends.
3. **Difference in Wavelength**: The wavelength of light also changes when it moves from one medium to another, which can influence the refraction.

**Hint:** Think about how each of these factors relates to the behavior of light as it transitions between media.

### Step 3: Analyze the Options
Given the options:
- 1. Difference in refractive index
- 2. Difference in velocities
- 3. Difference in wavelength
- 4. All of the above

Since all three factors contribute to the phenomenon of refraction, we can conclude that the correct answer is option 4: "All of the above".

**Hint:** Consider how each factor is interconnected and contributes to the overall effect of refraction.

### Final Answer
The correct answer is: **All of the above** (Option 4).