# Thread: Properties Of Air Quiz

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1) When the dry bulb temperature increases, the relative humidity

a. increases
b. decreases
c. remains the same
d. none of these

2) When the dry bulb temperature increases, the specific humidity

a. increases
b. decreases
c. remains the same
d. none of these

Assume no other process is involved other than increasing the dry bulb temperature. This is a simple sensible heat process.

[Edited by NormChris on 08-08-2004 at 05:58 PM]

2. b
c

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I'm going with,

B and C

Yuma,

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## OH! Specific Humidity...

A. increases
specific humidity stays the same in sensible heat change

[Edited by highlimit on 08-08-2004 at 06:38 PM]

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Originally posted by highlimit
A. increases
A. increases,but I've never heard of specific humidity
That's good because that is why we are dong this quiz thing, to learn.

Relative humidity is just that "relative". It tells us the percentage but not specifically how "much" water vapor is in the air.

Relative humidity is like saying the glass is half-full (50%) of water but we don't know how large the glass is so we don't know how many ounces of water are in the glass.

Specific humidity is more exact. Specific humidity is like saying there are 4 ounces of water in an 8 ounce glass. The glass is still half full but now we are specifically stating exactly how much water is in the glass.

The relative humidity of air is stated in %. Specific humidity is stated in grains of water vapor per pound of air. It can also be stated in decimal fractions of a pound of water vapor per pound of air.

6. B
C
I also found a wonderful website with a downloadable psych program that allows you to take and plot certain characteristics. I do not know the cost but for the free version it is pretty nice.

7. b. c.

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A and A if what NormChris said is correct.correct me if i am wrong.

9. A
C

10. b.....c....

11. B, C

12. B before C

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## NormChris quiz- The temp. rise & humidity

I must admit that I read the term relative humidity as
just plain old HUMIDITY, until I read the rest of the question.
How conditioned we are to terms used so often (or loosely). Anyway, Norm gave away the answer to the specific humidity part when he said it is measured in water content per pound of air.

Remember (way back) that air expands as it gets hotter, therefore it takes-up more space and thus allows more moisture to be contained within its space. But if the moisture available does not change, then the humidity (relative to the temp.) will be less because it has more space to dispurse itself.So, B. is the answer. In part 2 of the ques. we do not care about space because a pound of air weighs a pound no matter how much space it occupies. Therefore, C. would be the answer.
I almost was going to go with A. as the answer for 1st part of the ques., but even though the humidity CAN increase when the temp. rises, the ques. was not what can happen, but what does occur when all else stays the same.

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