ASNT Industrial Radiography Radiation Safety Practice Test

How do wavelike radiation waves travel?

1. At varying speeds depending on conditions

2. At the speed of light regardless of external factors

3. Slowly when subject to magnetic fields

4. Only through a vacuum

The correct answer is: At the speed of light regardless of external factors

Wavelike radiation waves, such as electromagnetic waves, travel at the speed of light in a vacuum. This speed is approximately 299,792 kilometers per second (about 186,282 miles per second) and is considered a fundamental constant of nature. While the speed of light can be affected when passing through different media, the question specifically addresses the characteristic travel speed of radiation waves in general. This means that regardless of various external factors, in a vacuum, these waves maintain this constant speed. It's important to note that while other conditions such as medium density and temperature can affect signal propagation, these variations do not alter the fundamental nature of the radiation itself. Instead, they cause changes in speed when traveling through different materials, but the question emphasizes their behavior in a basic context, which aligns with the choice of traveling at the speed of light.