Question:
Velocity of light is maximum in:
Velocity of light is maximum in:
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The speed of light is always fastest in a vacuum. In any medium with a refractive index greater than 1, the speed of light is slower.
Updated On: Feb 3, 2026
- Vacuum
- Water
- Diamond
- Glass
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The Correct Option is A
Solution and Explanation
Step 1: Understanding the behavior of light in different mediums.
The speed of light depends on the medium through which it travels. In a vacuum, the speed of light is the fastest, traveling at approximately \( 3 \times 10^8 \, \text{m/s} \). Light travels slower in any medium with a refractive index greater than 1, such as water, glass, or diamond. The refractive index \( n \) of a medium is a measure of how much light slows down in that medium compared to its speed in a vacuum.
Step 2: Comparing the refractive indices of different substances.
- The refractive index of a vacuum is \( n = 1 \), meaning light travels at its maximum speed.
- The refractive index of water is approximately \( n = 1.33 \).
- For glass, the refractive index is around \( n = 1.5 \).
- For diamond, the refractive index is even higher, approximately \( n = 2.42 \).
Step 3: Conclusion.
Since light travels fastest in a vacuum, the velocity of light is maximum in a vacuum, which corresponds to option (A).
The speed of light depends on the medium through which it travels. In a vacuum, the speed of light is the fastest, traveling at approximately \( 3 \times 10^8 \, \text{m/s} \). Light travels slower in any medium with a refractive index greater than 1, such as water, glass, or diamond. The refractive index \( n \) of a medium is a measure of how much light slows down in that medium compared to its speed in a vacuum.
Step 2: Comparing the refractive indices of different substances.
- The refractive index of a vacuum is \( n = 1 \), meaning light travels at its maximum speed.
- The refractive index of water is approximately \( n = 1.33 \).
- For glass, the refractive index is around \( n = 1.5 \).
- For diamond, the refractive index is even higher, approximately \( n = 2.42 \).
Step 3: Conclusion.
Since light travels fastest in a vacuum, the velocity of light is maximum in a vacuum, which corresponds to option (A).
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