PADI, Open Water Diver, Final Exam Review Correctly
Answered
1) If an object is neutrally buoyant (does not sink or float) in fresh water, the same object placed into
salt water would
A sink.
B either sink or float.
C do nothing.
D float. - Ans-D float.
Salt water is heavier than fresh water because it has dissolved minerals in it. This means it causes more
upward force (buoyancy) on an object. An object that is neutrally buoyant in fresh water would float in
salt water because there is greater upward force.
See Being a Diver I - Buoyancy and Controlling Buoyancy.
2) I blow up a balloon, tie it off, and take it to the bottom of the swimming pool. What will happen to the
balloon and the air inside it?
A The balloon will get bigger and the air inside the balloon will be less dense (molecules move further
apart).
B The balloon will get smaller and the air inside the balloon will be more dense (molecules move closer
together).
C The balloon will get bigger and the air inside the balloon will be more dense.
D The balloon will get smaller and the air inside the balloon will be less dense. - Ans-B The balloon will
get smaller and the air inside the balloon will be more dense (molecules move closer together).
As water pressure increases, the volume of an air space will decrease. This causes the density of the air
inside to increase and air molecules are pushed closer together. The balloon would get smaller and the
air density inside would be greater.
,See Being a Diver I - Water Pressure and Air Volume Effects.
3) I turn a glass upside down, trap the air in it by putting it in water, and then I take the glass down to 10
meters. The air space would
A become half the size it was at the surface.
B not change in size.
C become 1/3 the size it was at the surface.
D become 2/3 the size it was at the surface. - Ans-A become half the size it was at the surface.
At 10 meters, the pressure is 2 bar. An air volume taken to this depth from the surface would decrease
and become half the size.
See Being a Diver I - Water Pressure and Air Volume Effects.
4) If I am not able to equalize (clear) my body air spaces, it may be because I have
A seasickness.
B heart disease and high blood pressure.
C a cold, allergy or another medical problem.
D anxiety. - Ans-C A cold, allergy or another medical problem.
A cold, or any congestion, can block air passages in your ears and sinuses, making equalization difficult
or impossible.
See Being a Diver I - The Effects of Increasing Pressure on Body Air Spaces.
5) If my ears or sinuses hurt while I am descending (going down), it usually means
A my air spaces are equalized.
, B my mask strap is too tight.
C I am feeling a squeeze and need to equalize.
D my mask is too small. - Ans-C I am feeling a squeeze and need to equalize.
Pain in your ears or sinuses means that they aren't equalized. Stop your descent and ascend slightly to
relieve pressure on your ears. Then attempt to equalize again. If you can't equalize, end the dive.
See Being a Diver I - The Effects of Increasing Pressure on Body Air Spaces.
6) The best place for me to position an alternate air source is
A loose by my side so I can find it fast.
B in the triangle area formed by my chin and the lower corners of my rib cage.
C to the base of my cylinder.
D to the back of my BCD between my shoulder blades and waist. - Ans-B In the triangle area formed by
my chin and the lower corners of my rib cage.
Your alternate air source attaches with a quick release in the triangle area formed by your chin and the
lower corners of your rib cage. Avoid letting your alternate air source dangle unsecured from your kit.
See Equipment I - Regulators.
7) Lung overexpansion injuries can be caused by
A scuba diving without a buddy.
B continuing a dive when not properly weighted.
C not drinking enough water before scuba diving.
D holding my breath while scuba diving. - Ans-D Holding my breath while scuba diving.
Answered
1) If an object is neutrally buoyant (does not sink or float) in fresh water, the same object placed into
salt water would
A sink.
B either sink or float.
C do nothing.
D float. - Ans-D float.
Salt water is heavier than fresh water because it has dissolved minerals in it. This means it causes more
upward force (buoyancy) on an object. An object that is neutrally buoyant in fresh water would float in
salt water because there is greater upward force.
See Being a Diver I - Buoyancy and Controlling Buoyancy.
2) I blow up a balloon, tie it off, and take it to the bottom of the swimming pool. What will happen to the
balloon and the air inside it?
A The balloon will get bigger and the air inside the balloon will be less dense (molecules move further
apart).
B The balloon will get smaller and the air inside the balloon will be more dense (molecules move closer
together).
C The balloon will get bigger and the air inside the balloon will be more dense.
D The balloon will get smaller and the air inside the balloon will be less dense. - Ans-B The balloon will
get smaller and the air inside the balloon will be more dense (molecules move closer together).
As water pressure increases, the volume of an air space will decrease. This causes the density of the air
inside to increase and air molecules are pushed closer together. The balloon would get smaller and the
air density inside would be greater.
,See Being a Diver I - Water Pressure and Air Volume Effects.
3) I turn a glass upside down, trap the air in it by putting it in water, and then I take the glass down to 10
meters. The air space would
A become half the size it was at the surface.
B not change in size.
C become 1/3 the size it was at the surface.
D become 2/3 the size it was at the surface. - Ans-A become half the size it was at the surface.
At 10 meters, the pressure is 2 bar. An air volume taken to this depth from the surface would decrease
and become half the size.
See Being a Diver I - Water Pressure and Air Volume Effects.
4) If I am not able to equalize (clear) my body air spaces, it may be because I have
A seasickness.
B heart disease and high blood pressure.
C a cold, allergy or another medical problem.
D anxiety. - Ans-C A cold, allergy or another medical problem.
A cold, or any congestion, can block air passages in your ears and sinuses, making equalization difficult
or impossible.
See Being a Diver I - The Effects of Increasing Pressure on Body Air Spaces.
5) If my ears or sinuses hurt while I am descending (going down), it usually means
A my air spaces are equalized.
, B my mask strap is too tight.
C I am feeling a squeeze and need to equalize.
D my mask is too small. - Ans-C I am feeling a squeeze and need to equalize.
Pain in your ears or sinuses means that they aren't equalized. Stop your descent and ascend slightly to
relieve pressure on your ears. Then attempt to equalize again. If you can't equalize, end the dive.
See Being a Diver I - The Effects of Increasing Pressure on Body Air Spaces.
6) The best place for me to position an alternate air source is
A loose by my side so I can find it fast.
B in the triangle area formed by my chin and the lower corners of my rib cage.
C to the base of my cylinder.
D to the back of my BCD between my shoulder blades and waist. - Ans-B In the triangle area formed by
my chin and the lower corners of my rib cage.
Your alternate air source attaches with a quick release in the triangle area formed by your chin and the
lower corners of your rib cage. Avoid letting your alternate air source dangle unsecured from your kit.
See Equipment I - Regulators.
7) Lung overexpansion injuries can be caused by
A scuba diving without a buddy.
B continuing a dive when not properly weighted.
C not drinking enough water before scuba diving.
D holding my breath while scuba diving. - Ans-D Holding my breath while scuba diving.
