Multiple choice

One inch of mercury corresponds to how much difference in altitude?

  1. 1000 feet

  2. 1500 feet

  3. 30 feet

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

One inch of mercury (inHg) is a larger pressure unit than hPa. 1 inHg ≈ 33.86 hPa. Since 1 hPa ≈ 30 feet, 1 inHg ≈ 33.86 × 30 ≈ 1016 feet (commonly rounded to 1000 feet). This is a standard conversion used in aviation - 1000 feet per inch of mercury is the practical approximation. 30 feet is far too small (that's for 1 hPa).

Keep practicing — related questions