Dive Theory

Practice Exam D

Dive Theory Practice Exam D

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PADI Instructor Development Dive Theory Exam

Constants used for Dive Theory Exams

Metric

1 litre of salt water weighs 1.03 kilograms

1 litre of fresh water weighs 1 kilogram

Pressure increases by 1 ATM every 10 metres of salt water

Pressure increases by 1 ATM every 10.3 metres of fresh water

Pressure changes per unit of salt water = 0.100 ATM/m

Pressure changes per unit of fresh water = 0.097 ATM/m

Physics

1) If a 50 litre flexible, sealed air filled container is
taken from the surface to 30m, how much air needs
to be pumped from the surface to fill the container
in sea water?
a) 150 litres
b) 194 litres
c) 195 litres
d) 200 litres

2) If both a balloon and a scuba tank are filled in an air-
conditioned room and then stored outside in direct
sunlight. What will happen to the balloon and the
scuba tank?
a) the volume of the balloon will increase and the
pressure in the scuba tank will increase.
b) the volume of the balloon will decrease and the
pressure in the scuba tank will decrease.
c) the volume of the balloon and scuba tank will
both increase.
d) the pressure of the balloon and scuba tank will
both increase.

3) If a filled scuba tank contains 1.5% of carbon
monoxide at the surface, what percentage of
carbon monoxide will the scuba tank contain at 30m?
a) 6 %
b) 3 %
c) 1.5 %
d) 0.4 %

4) If a scuba tank is filled and contains 1.25 % of carbon
dioxide at the surface, what effect will it have if a diver
were to breathe it at 30m of sea water?
a) 1.25 %
b) 5 %
c) 3.75 %
d) 7.25 %

5) If a balloon is taken from 30m to 10m in sea water,
assuming that no gas escapes and the balloon does
not burst, what will the new volume be?
a) Half the original volume.
b) Double the original volume.
c) Four times the original volume.
d) The answer can not be determined.

6) In water, heat is conducted _____ faster than on land
compared to sound which travels _________ faster
underwater than on land.
a) 20/4
b) 14/6
c) 6/60
d) 4/20

7) When underwater, ____________________ is the most
effective form of heat loss while ________________ is
the least effective.
a) conduction/convection
b) convecton/radiation
c) conduction/radiation
d) convection/conduction

8) Underwater, _____________ can cause objects to look
further away than they really are.
a) using a torch
b) refraction
c) counter contrast
d) turbidity

9) If a diver breathes 100 bar of air in 20 minutes at 20m
of sea water, how much air would he breathe in 10
mins at 10m of sea water?
a) 33 bar
b) 20 bar
c) 50 bar
d) 100 bar

10) If a diver breathes PPO2 0.25% of O2 at 1 ATM, what is
the PPO2 % of O2 at 3 ATM?
a) 1%
b) 0.75%
c) 0.5%
d) 0.25%

11) If an object weighs 250 kg and displaces 65 litres,
how much water needs to be displaced to achieve
neutral buoyancy in 30m of fresh water?
a) 185 litres
b) 200 litres
c) 740 litres
d) 315 litres

12) If a scuba tank contains 0.5% of carbon dioxide at the
surface, what % effect will the carbon dioxide have on
a diver at 95m?
a) 0.5%
b) 0.3%
c) 4.75%
d) 5.25%

Physiology

1) If a diver experiences numbness on one side of the
body immediately upon surfacing from a dive you
should suspect:
a) decompression sickness
b) heat stroke
c) vertigo
d) air embolism

2) If a diver surfaces and you notice they have bright
red lips what illness is the diver likely to be suffering
from?
a) decompression sickness
b) carbon monoxide poisoning
c) oxygen toxicity
d) air embolism

3) What type of barotrauma can result in AGE?
a) lung barotrauma
b) sinus barotrauma
c) inner-ear barotrauma
d) equipment barotrauma

4) Very small bubbles of nitrogen are known as:
a) silent bubbles
b) invisible bubbles
c) tiny bubbles
d) none of the above

5) What part of the body is a diver likely to damage
if they try to force equalization?
a) a reverse squeeze
b) an eardrum rupture
c) an oval window rupture
d) a round window rupture

6) What condition is a diver suffering from if he
complains of a tight neck seal and feeling
light-headed?
a) carotid-sinus reflex
b) carbon monoxide poisoning
c) oxygen toxicity
d) decompression sickness

7) A rapid decrease in ambient pressure surrounding a
diver can result in?
a) decompression sickness
b) silent bubbles
c) oxygen toxicity
d) both a and b are correct

8) An enriched air diver who makes a dive that exceeds an
oxygen partial pressure of 1.4-1.6 ata runs an
unacceptable risk of?
a) convulsion and drowning due to pulmonary
oxygen toxicity
b) decompression sickness
c) convulsion and drowning due to CNS oxygen
toxicity.
d) subcutaneous emphysema

9) Excessive hyperventilation (more than three or four
breaths) before a breath hold dive can cause:
a) an excessive urge to breath underwater.
b) hypercapnia.
c) the carotid sinus reflex.
d) a diver to black out in shallow water without
warning.

10) Oxygen is recommended for DCS first aid because:
a) it accelerates nitrogen elimination and raises
blood oxygen levels.
b) it dilates blood vessels in the limbs to reduce
limb pain.
c) it forces bubbles back into solution.
d) all of the above.

11) For which lung overexpansion injury would you give the
patient emergency oxygen and apply other first aid for
DCI steps?
a) air embolism
b) pneumothorax
c) mediastinal emphysema
d) all of the above

12) The primary first aid for DCI is:
a) to elevate the patients legs.
b) to have the patient return to the water for
recompression.
c) to administer oxygen.
d) all of the above.

Recreational Dive Planner

1) When diving at altitude using the RDP above ______ requires the use of special procedures:
a) 300 metres or 1000 feet
b) 500 metres or 1500 feet
c) 2400 metres or 8000 feet
d) 3000 metres or 10,000 feet

2) Diving at altitude, requires the use of special
procedures including the conversion of actual depth
to theoretical depth. To use theoretical depth
tables, you must know the ________________.
a) planned actual dive depth
b) altitude of the dive
c) both a and b
d) barometric pressure at altitude

3) Flying after diving recommendations suggest that
divers wait _________ hours after completing a
single dive and ________ hours after completing
multiple dives for several days before flying in a
commercial jet airliner.
a) 12 / 24
b) 4 / an extended period beyond 12
c) 24 / an extended period beyond 24
d) 12 / 18

4) The Recreational Dive Planner model is
characterised by:
a) 6 compartments and a 120 minute surface
interval washout.
b) 14 compartments and a 60 minute surface
interval washout
c) 5 compartments and EE surface interval
washout.
d) None of the above.

5) What are the recommended procedures for using
dive computer while diving?
a) A buddy team may dive with only one
computer if the divers remain side-by-side.
b) If one diver’s computer fails during the dive,
the diver may continue the dive using the
buddy’s computer.
c) Each diver must have a computer and the
buddy team should follow the most
conservative computer.
d) Both a and b.

6) The U.S. Navy tables repetitive dive credit is based
on a _________________ & the RDP repetitive dive
credit on a __________________.
a) high M-Value, controlling compartment
b) 60 minute halftime / 120 minute halftime
c) 120 minute halftime / 60 minute halftime
d) EE washout, 720 minute washout

Use the eRDPml to answer the following:

7) A dive to 18 metres for 40 minutes yields what
pressure group?
a) P
b) N
c) M
d) Q

8) You dive to 17 metres for 27 minutes. After a 32
minute surface interval, what is your pressure group?
a) F
b) D
c) G
d) E

9) What is the minimum surface interval required between
a dive to 18 metres for 50 minutes followed by a dive
to 14 metres for 60 minutes.
a) 48 minutes
b) 47 minutes
c) 42 minutes
d) 40 minutes

10) What is the minimum surface interval required to make
the following dive? Pressure group after previous
dive: S. Second dive: 16 metres for 60 min.
a) 2:39
b) 2:41
c) 2:43
d) 2:45

11) You plan to make three dives. The first will be to 23m
for 30 minutes, followed by a one hour, 30 minute
surface interval. The second dive will be to 22 m for
18 minutes. If this is followed by a one hour, 20 minute
surface interval, what is the no decompression limit for
a repetitive dive to 16 m?
a) 58 minutes
b) 55 minutes
c) 50 minutes
d) 52 minutes

12) A diver plans to do three dives using minimum surface
intervals. The planned dive profiles are: 12 metres for
92 minutes, 33 metres for 13 minutes and 16 metres
for 54 minutes. Arrange the dives in appropriate order
and calculate how many total minutes it will take to
complete from descent of the first dive to surfacing on
the last dive (you may ignore ascent time, but not
required safety stop time.)
a) 278 minutes
b) 269 minutes
c) 262 minutes
d) 253 minutes

General Skills & The Environment

1) A rip current is caused by:
a) warm water meeting cold water.
b) a strong offshore wind.
c) fresh water meeting salt water.
d) water funnelling back to sea through a narrow
opening in a reef or sand bar.

2) The generally recommended knot for making a
reliable, easy-to-untie loop in a rope is:
a) the bowline
b) the sheet bend
c) the square knot
d) the clove hitch

3) In general terms, waves are caused by:
a) planetary motion
b) the gravitational pull of the moon
c) upwelling
d) wind

4) Aquatic life injury signs and symptoms may include:
a) numbness or paralysis
b) cardiac arrest
c) severe pain
d) all of the above

5) If you encounter a thermocline while descending,
you will experience:
a) an abrupt transition from salt water to fresh
water which makes your vision seem blurred.
b) a cool current rising up from the bottom.
c) a gradual change to salt water.
d) an abrupt transition to colder water.

6) Of those listed, what is the most accurate method
of measuring distance underwater?
a) Kick cycles
b) Arm spans
c) Timed swim
d) Air consumption

7) The two forms of stress that can affect divers are:
a) physical stress and panic stress.
b) psychological stress and panic stress.
c) physical stress and psychological stress.
d) panic stress and anxiety stress.

8) The generally preferred method for providing rescue
breaths to a nonbreathing diver at the surface is:
a) mouth to pocket mask
b) mouth to mouth
c) mouth to nose
d) mouth to snorkel

9) An alternate air source must:
a) be identified by use of a colour different than that
of the primary regulator.
b) be located in the triangle formed by your chin
and the corners of your rib cage.
c) be located on the right hand side of the first
stage and come around the right hand side of the
diver.
d) All of the above

10) When using a compass to navigate a square pattern
with four sides the same length, set your bezel to
turn ______ degrees at each corner:
a) 45
b) 120
c) 180
d) 90

11) A diver checks for proper weighting by:
a) deflating the BCD while holding a normal breath
so that the diver floats at eye level.
b) taking a big breath in and fully deflating the BCD.
c) deflating the BCD completely and exhaling.
d) deflating the BCD while holding a normal breath
so that the diver floats with his head and neck
out of the water.

12) If you are standing on a boat facing the stern, the side
to your left is:
a) bow
b) aft
c) port
d) starboard

Equipment

1) Scuba tanks should be visually inspected to detect
or prevent which of the following:
a) internal and external corrosion.
b) contamination build up inside the tank.
c) possible galvanic action between the threads
of the valve and the tank neck.
d) all of the above

2) Regarding downstream valve second stage models:
a) they’re mechanically simple and therefore
highly reliable.
b) the air flow pushes against them, so they’re
easy to set so they’re just barely closed which
makes it easy to breathe.
c) fail safe design
d) all of the above

3) A(n) _____________ design of regulator release
exhaled air directly into the water:
a) free flow
b) open circuit
c) balanced
d) fail safe

4) Scuba that recycles exhaled gas, receives a steady
flow of fresh gas and allows a steady escape of
excess gas is:
a) open circuit scuba
b) semiclosed circuit scuba
c) closed circuit scuba
d) none of the above

5) A K valve is:
a) a simple on-off valve
b) a valve with a reserve mechanism
c) a valve that takes a yoke screw design
regulator
d) None of the above

6) A burst-disk is intended to protect against:
a) inhaling water when breathing from a snorkel.
b) rupturing a BCD if it is overinflated.
c) damage to a scuba tank that may occur from
accidental overfilling.
d) none of the above

7) When filling a scuba tank equipped with a J-valve:
a) the reserve lever must be in the down position.
b) the reserve lever must be in the centre neutral
position.
c) the reserve lever must be in the up position. GUESS
d) the reserve lever must be in the 20-40 bar position.

8) An upstream valve is one that:
a) opens against the flow of air.
b) opens with the air flow.
c) may open with or against the air flow depending
on the design
d) is any valve in the first stage.

9) The purpose of the environmental seal in the first stage
of a regulator is:
a) to keep the regulator from freezing in cold water.
b) to act as a pollution filter.
c) to protect environments such as caverns & caves.
d) to stop salt water entering the regulator.

10) Before using an enriched air cylinder, each diver must
analyze the contents to confirm the ____________, so
so they can set their enriched air dive computers
properly.
a) percentage of nitrogen.
b) cylinder pressure.
c) cylinder capacity.
d) percentage of oxygen.

11) A scuba tank should not be filled with 100% oxygen
because:
a) The working pressure is different.
b) Cylinders containing pure oxygen need to be
cleaned, lubricated and prepared to a higher
standard.
c) Oxygen cylinders need more capacity.
d) None of the above.

12) What is the most common cylinder valve problem?
a) Internal corrosion.
b) A worn or missing O ring.
c) A missing burst disk.
d) A missing dust cap.