Science
MediumQ. No. what-is-the-maximum-speed-of-light
What is the maximum speed of light?
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AIn water
BIn glass
CIn vacuum (3 × 10⁸ m/s)
DIn diamond
Correct Answer: In vacuum (3 × 10⁸ m/s)Your Answer: C
The speed of light varies in different media and has a maximum value in vacuum. Option A is wrong. Speed of light in water is 2.25 × 10⁸ m/s which is less than in vacuum. The refractive index of water is approximately 1.33 meaning light slows down by a factor of 1.33 in water compared to vacuum. Option B is wrong. Speed of light in glass is approximately 2 × 10⁸ m/s which is even slower than in water. Glass has a higher refractive index (~1.5) than water. Option C is CORRECT. The image states: प्रकाश की सर्वाधिक चाल कहाँ होती है — निर्वात में (3 × 10⁸ m/sec). The speed of light in vacuum is c = 3 × 10⁸ m/s = 300,000 km/s. This is the maximum speed of light and indeed the maximum speed possible for any object with mass in the universe (according to special relativity). Light slows down when it enters any material medium because it interacts with the atoms. The ratio c/v (speed in vacuum/speed in medium) gives the refractive index of that medium. Option D is wrong. Diamond has one of the highest refractive indices among natural materials (~2.42) meaning light slows dramatically to about 1.24 × 10⁸ m/s in diamond — much less than in vacuum.
FAQ
Common questions and clear answers for this topic.
Optics is the branch of physics that studies the behavior of light, including its reflection, refraction, and interaction with lenses and mirrors.
Reflection is the bouncing back of light when it strikes a surface, while refraction is the bending of light as it passes from one medium to another with a different optical density.
A lens is a transparent optical device with curved surfaces that refracts light to converge or diverge rays, commonly classified as convex (converging) or concave (diverging).
The speed of light in a vacuum is approximately 3 x 10^8 meters per second, denoted by the symbol c.
Total internal reflection occurs when light traveling from a denser medium to a rarer medium strikes the boundary at an angle greater than the critical angle, causing it to be completely reflected back into the denser medium.
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