The speed of photons in vacuum is _ than in liquid water?
Correct answer: A. Higher
- A. Higher
- B. Smaller
- C. Equal
- D. None of these options is correct
Explanation
The speed of photons in a vacuum is greater than in liquid water. In a vacuum, such as outer space, photons travel at the speed of light, which is approximately 299,792,458 meters per second (or about 186,282 miles per second). In contrast, the speed of light in a material medium like liquid water is slightly slower than its speed in a vacuum due to interactions between the photons and the atoms or molecules of the medium. In water, the speed of light is approximately 225,000,000 meters per second (about 3/4 of its speed in a vacuum). This difference in speed is due to the refractive index of the medium, which quantifies how much light is slowed down when it passes through the material compared to a vacuum.
Last updated
About Nuclear Physics
Atomic nuclei contain protons and neutrons, with nuclear size, mass defect and binding energy describing their stability. The work covers alpha, beta and gamma decay, decay equations, half-life and decay rate, along with radiation safety and medical applications such as imaging, radiotherapy and tracers.
Practise Nuclear Physics
1,254 free Nuclear Physics MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Physics questions like this
Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.