Question T5C07
From subelement T5 - T5C
What is the abbreviation for megahertz?
Why is this correct?
MHz is the correct abbreviation for megahertz. The 'M' must be capitalized because it represents 'mega-' (one million), and 'Hz' must be capitalized because it represents 'hertz,' the unit of frequency. Options A and B are wrong because they omit the 'z' from hertz. Option C is wrong because the 'H' in Hz must be capitalized - hertz is named after Heinrich Hertz, requiring the capital H.
Memory tip
Remember the pattern: metric prefixes like mega (M) are capitalized for large values, while unit symbols follow specific capitalization rules. Hz always has a capital H, making this a consistent rule across all frequency abbreviations like kHz, MHz, and GHz.
Learn more
In amateur radio frequency coordination, precise notation matters when documenting frequency privileges in band plans. The International System of Units (SI) requires MHz notation in official frequency allocations - you'll see this standard format on your license, in Part 97 frequency tables, and when programming transceivers. Incorrect abbreviations could cause confusion in emergency communications or repeater coordination where precise frequency identification is critical.
Think about it
Why do you think international standards require such specific capitalization rules for units like Hz, and what problems might arise in radio communications if operators used inconsistent abbreviations?