Depending on the region and if its commercial or residential its 6 to 9 inches.
Approximately the distance between this answer and your question.
it is maximum 120 m .
lamda /2
about 30 centimeters
In a room, the maximum distance between duplex outlets is usually 12 feet. Too much distance between outlets can make it difficult to plug in all of the necessary electrical devices in a room.
Maximum Permitted Mileage
30mph
The maximum distance between two near field communication devices is typically around 4 centimeters or 1.6 inches.
The ideal R-value for sleeping pads to ensure maximum comfort and insulation during outdoor adventures is typically between 3 and 5.
I'm sure that this question means altitude. Altitude is vertical distance between the maximum or minimum of the ocean wave (or any wave) and halfway between the minimum and maximum. Half the vertical distance between the minimum and maximum of the wave.
12 feet
The distance is 457 km - 5 hours maximum!