1 mega ohms or 1 mega ohm?

[gorikaz]

Dear teachers,

I know that 1 MΩ is correct, with no plural form with a unit (Ω).
However, what about if you spell out?
"1 mega ohm" or "1 mega ohms"??
Which one (singular or plural) is correct?

I used to think that using a plural form (e.g., "ohms" in this case)
is correct as long as the number is more than one (1)--I mean not "1 million" or "1 mega" etc. but purely "one (1)".

Also, how about the number like 0.5?
Should it be treated as plural, thus "0.5 seconds" is correct (not "0.5 second")?

Hmmm, someone, please help me!

[5jj]

"1 mega ohm" or "1 mega ohms"?

It's one megaohm.

Also, how about the number like 0.5?
Should it be treated as plural, thus "0.5 seconds" is correct (not "0.5 second")?

It's nought point five seconds or half a second.

[Tdol]

We use the plural for numbers bigger and smaller (in decimals- 0.5 + unit) than one. 1 mega/nano/giga, etc, are not plural- they are one of that unit, even though that unit is made up of thousands or millions of something else- 1 megabyte = 1,000 or 1,024 (depending on the definition) bytes.

[SoothingDave]

Remember that when we use it as an adjective it is always singular. We may measure 2500 ohms in a circuit, but would speak of a 2500 ohm resistor.

[emsr2d2]

And when used as an adjective, it would normally be hyphenated:

I have a 2500-ohm resistor.
I went on a 7-week holiday.
It's a 1000-dollar watch.

[gorikaz]

Thank you all for your help.
I see, not plural in a case of 1 megaohm, 1 gigabyte, 1 kilometer, etc.
(except in the case of an adjective form).

[Rover_KE]

I see, not plural in a case of 1 megaohm, 1 gigabyte, 1 kilometer, etc.
(except in the case of an adjective form).

No—not plural there, either. Reread Dave's reply in post #4.

Rover

[Tdol]

Thank you all for your help.
I see, not plural in a case of 1 megaohm, 1 gigabyte, 1 kilometer, etc.
(except in the case of an adjective form).

Never as an adjective.