What is the approximate velocity of a radio wave in free space?

The approximate velocity of a radio wave in free space is 300,000,000 meters per second, which is equivalent to the speed of light. This is a fundamental property of electromagnetic waves, including radio waves, as they propagate at light speed in a vacuum. The speed of light is a critical constant in physics, often denoted as "c," and underpins many calculations and theories related to electromagnetism and wave propagation.

In practical terms, this high speed allows radio waves to travel vast distances quickly, which is essential for communication systems that rely on radio frequency signals, such as broadcasting and amateur radio. Understanding the speed of radio waves helps technicians in designing and troubleshooting systems to ensure effective communication.

The other choices do not reflect the correct speed of radio waves. For instance, 150,000 meters per second is significantly slower than the actual speed and does not align with the established scientific understanding. Similarly, while 300,000,000 miles per hour seems high, it's not an accurate conversion from meters per second to miles per hour, leading to confusion. Finally, 150,000 miles per hour is far below the velocity of light and does not qualify as an appropriate measure for radio wave speed.