Air Pressure

Q. A rubber sucker, when pressed on a surface sticks to it, because:

1. gravitational pull acts on it
2. atmospheric pressure acts on it externally
3. rubber sucker has some glycerin in it
4. the suckers have a very strong adhesive which holds it in place

Q. You would experience more atmospheric pressure if you were ______.

1. on the roof of a tall building
2. on top of a mountain
3. skydiving from $4000m$ above ground
4. on the sea level

Q. We generally use ______ to make a barometer.

1. air
2. mercury
3. water
4. oxygen

Q. Why could they not set any sail on the main mast on 4 January?

Q. The author provides information that answers which of following questions?
1. What causes the disturbances that change the cloud from its original static condition?
2. How does this small region's increasing density affect its gravitational field?
3. What is the end result of the gradually increasing concentration of the small region of gas?

1. 1 only
2. 2 only
3. 1, 2 and 3
4. 2 and 3 only