AM is typically associated with which advantage?

AM is typically associated with which advantage?

• A. Transmits farther than FM
• B. Cheaper to produce
• C. Requires more power
• D. Wider bandwidth

Answer: (A)

The key idea is how radio waves propagate at different frequencies. AM uses lower frequencies, so its signals travel as ground waves that follow the curvature of the Earth and attenuate more slowly with distance than higher-frequency FM signals. This allows an AM station to cover a much larger area with the same power, and at night some AM signals can even bounce off the ionosphere for very long-range reception. That propagation behavior is what gives AM its characteristic advantage of longer reach. The other statements don’t describe this benefit: power requirements aren’t inherently lower for AM the way distance is, and while FM provides better sound quality, it travels primarily by line of sight and doesn’t reach as far under the same power. FM also uses a wider bandwidth, which is the opposite of AM’s typical bandwidth characteristics.

The key idea is how radio waves propagate at different frequencies. AM uses lower frequencies, so its signals travel as ground waves that follow the curvature of the Earth and attenuate more slowly with distance than higher-frequency FM signals. This allows an AM station to cover a much larger area with the same power, and at night some AM signals can even bounce off the ionosphere for very long-range reception. That propagation behavior is what gives AM its characteristic advantage of longer reach. The other statements don’t describe this benefit: power requirements aren’t inherently lower for AM the way distance is, and while FM provides better sound quality, it travels primarily by line of sight and doesn’t reach as far under the same power. FM also uses a wider bandwidth, which is the opposite of AM’s typical bandwidth characteristics.