Which portion of the radio spectrum is used for standard AM (Amplitude Modulation) broadcast transmission?

Introduction / Context:
Radio services are categorized by frequency bands, each with distinctive propagation and usage patterns. Standard AM broadcast radio (the familiar medium-wave band) occupies a well-defined slice of spectrum. Knowing these band limits is foundational for communications engineering and exam questions on spectrum allocation.

Given Data / Assumptions:

• The question concerns standard AM broadcast, not shortwave or FM broadcast.
• We use conventional ITU band naming (VLF, LF, MF, HF, VHF, etc.).
• Approximate decimal ranges are acceptable for classification.

Concept / Approach:
AM broadcast (medium-wave) lies in the Medium Frequency (MF) band. Typical channel plans place AM broadcast from roughly 530 kHz to 1700 kHz in many regions, which is squarely within the MF range of 300 kHz to 3 MHz. Other bands (HF and VHF) are used for shortwave broadcasting and FM/TV services respectively, not standard medium-wave AM.

Step-by-Step Solution:

Verification / Alternative check:
Regulatory charts and textbooks list AM broadcast allocations inside MF, while HF (3–30 MHz) covers shortwave services and VHF (30–300 MHz) includes FM broadcast near 88–108 MHz. This confirms the MF choice is correct for standard AM broadcast.

Why Other Options Are Wrong:

• VLF (3–30 kHz): used for specialized long-range/underwater comms, not AM broadcast.
• HF (3–30 MHz): supports shortwave broadcasting, not standard medium-wave AM.
• VHF (30–300 MHz): home to FM broadcast and TV, not AM medium-wave.
• None: incorrect because the MF range option is correct.

Common Pitfalls:
Confusing AM “medium-wave” with shortwave (HF) AM; assuming “AM” generically means any amplitude-modulated service, whereas the question points to standard broadcast AM in the medium-wave band.

Final Answer:
Medium Frequency: 300 kHz to 3 MHz