IDC Guide

Dive Theory

Mock Exam B

Instructor Development Course – Diving Theory Mock Exam B

If you find this useful to your IDC Revision / Studies, you will be glad to hear that you can buy the full Exam Pack that includes 10 Standards and Dive Theory Mock PADI exams plus a bonus 75 question Pre-IDC Exam paper with answer keys.

Please click the link and BUY all 3 complete IDC revision packs that includes lots of revision documents and 11 practice mock exams, the exams include all the questions and answers you will need to revise to PASS the PADI IDC

PADI Instructor Development

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) The human body loses heat __ times faster in water

a) 4
b) 6
c) 14
d) 20

2) What is the gauge pressure at 26m in sea water?

a) 2.6 atm
b) 3.55 atm
c) 2.55 atm
d) 3.6 atm

3) What is the gauge pressure at 30m in fresh water?
a) 4 atm
b) 3 atm
c) 2.91 atm
d) 1.5 atm

4) If a sealed, flexible air filled container with a volume
of 3.5 litres at 32m of sea water is taken to 22m,
what would the new volume be?

a) 14 litres
b) 4.6 litres
c) 3.5 litres
d) 1.5 litres

5) If an object weighs 200 kg and displaces 65 litres,
how much water needs to be displaced to achieve
neutral buoyancy in 18m of fresh water?

a) 131 litres
b) 135 litres
c) 200 litres
d) 265 litres

6) If an object weighs 450 kg and displaces 340 litres
of sea water, how much water needs to be displaced
to make the object neutrally buoyant?

a) 97 litres
b) 107 litres
c) 110 litres
d) 123.5 litres

7) Sound travels ____ faster in water than in air?
than in air.

a) 20
b) 14
c) 4
d) no

8) A scuba tank containing 1% of carbon monoxide at the surface is taken to 30m. What percentage of carbon monoxide is in the scuba tank at this depth?

a) 4%
b) 3%
c) 2%
d) 1%

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
minutes at 10m of sea water?

a) 33 bar
b) 20 bar
c) 50 bar
d) 100 bar

10) Underwater, turbidity can cause objects to look further
away than they really are. This phenomenon is called:

a) inverse refraction
b) visual reversal
c) counter contrast
d) reflection

11) In a mixture of gases, the portion of the absolute
pressure exerted by one of the gases in the mix is
called?

a) partial pressure
b) gauge pressure
c) ambient pressure
d) atmospheric pressure

12) If the approximate partial pressure of nitrogen is 80%
& oxygen is 20% at sea level, what is the approximate
partial pressure of nitrogen at 3 ATM?

a) 0.8 ATA
b) 3.2 ATA
c) 0.6 ATA
d) 2.4 ATA

Physiology

1) Cigarette smoking prior to a dive should be avoided
a) it reduces the body’s ability to transport oxygen
b) it increases the risk of nitrogen narcosis
c) it raises the carbon monoxide level in the blood
d) both a and c are correct

2) During a deep dive a diver begins to act foolishly, as if he is intoxicated. This is probably caused by:
a) carbon monoxide poisoning
b) gas narcosis
c) decompression sickness
d) oxygen toxicity

3) Oxygen is administered to a diver suspected of
decompression illness to:
a) lower the partial pressure of nitrogen in the lungs which safely accelerates the diffusion of nitrogen from the blood
b) decrease hypocapnia
c) increase the metabolism of nitrogen
d) all of the above

4) Pressure changes most affect the ___ part of the ear
a) middle ear
b) outer ear
c) inner ear
d) all parts are affected equally

5) ____ is a substance contained within the ____ blood
cells that aids the transport of O2 around the body
a) Plasma / white
b) Cholesterol / red
c) Gamma globulin / red
d) Haemoglobin / red

6) Scuba tanks should not be filled with pure oxygen because:
a) breathing pure O2 under pressure can be toxic even at shallow depths
b) the body needs some nitrogen to function
c) the tank will not hold as much when filled
only with O2
d) the tank would corrode

7) Common signs and symptoms of carbon monoxide
because: poisoning include:
a) cherry red lips and fingernail beds
b) intoxication
c) numbness, tingling and / or paralysis
d) all of the above

8) What is the most serious lung over- expansion injury?
a) pneumothorax
b) mediastinal emphysema
c) air embolism
d) subcutaneous emphysema

9) Common signs and symptoms of a lung over-expansion injury may include:
a) dizziness, shock, paralysis or unconscious almost immediately upon surfacing
b) numbness and tingling in the extremities
c) difficulty breathing, chest pain
d) both a and c are correct

10) Deep Stomach Breathing increases breath hold time:
a) by decreasing the carbon dioxide levels in the lungs
b) reducing the body’s demand for oxygen
c) decreasing the level of nitrogen in the lungs
d) all of the above

11) After a dive, tiny nitrogen bubbles may be present in a diver’s circulation system yet
the diver may not display any symptoms of decompression illness. These bubblesare referred to as:
a) invisible
b) irregular
c) micro
d) silent

12) To avoid CNS Oxygen toxicity:
a) follow the oxygen exposure limits on the DSAT
Oxygen Exposure Table
b) don’t exceed an oxygen partial pressure of 2.0 ata
c) don’t exceed an oxygen partial pressure of 1.4 ata
d) none of the above

Recreational Dive Planner

1) Diving at altitude requires special procedures. How does the RDP define altitude diving?
a) 300 metres or greater
b) 3000 metres or greater
c) 100 metres or greater
d) 1000 metres or greater

2) In a decompression model, the rate at which a
theoretical tissue absorbs and releases nitrogen is called its:
a) compartment
b) M-value
c) halftime
d) controlling tissue

3) To determine the no decompression limits for the RDP a ___ tissue compartment
model was used and the surface interval credit table was calculated using a tissue half-time of ___.
a) 6 / 120 minutes
b) 14 / 120 minutes
c) 6 / 60 minutes
d) 14 / 60 minutes

4) The relationship between the body and Haldanean
decompression model is:
a) direct, with specific compartments relating to
specific physiology
b) not direct, but implied based on actual dive data
c) reliable only for no decompression diving
d) none of the above

5) The U.S. Navy tables use a ___________ to control
repetitive diving to accommodate _____________ ,
whereas the RDP uses a ______________ because
recreational dives are _______________.
a) 60 minutes halftime, stage decompression dives
120 minutes halftime, no stop dives
b) 60 minutes halftime, no stop dives
120 minutes halftime, air dives
c) 120 minutes halftime, stage decompression dives
60 halftime, no stop dives
d) 120 minute halftime, no stop dives
60 minute halftime, no stop dives

6) The minimum recommended surface interval before
flying after a single shallow dive is:
a) 4 hours
b) 8 hours
c) 12 hours
d) 24 hours

Use the eRDPml to answer the following:

7) What is the no decompression limit for a dive to 21m?
a) 37 minutes
b) 42 minutes
c) 45 minutes
d) 29 minutes

8) A diver exits the water in pressure group J, what is
the pressure group after a 42 minute surface interval?
a) A
b) B
c) C
d) D

9) A diver completes a 40 minute dive to 18m and after
waiting 45 minutes on the surface makes a second dive
to 14m for 45 minutes. What is the divers pressure
group after the second dive?
a) S
b) T
c) U
d) V

10) You are in pressure group S after previous dive. What is
the minimum surface interval to make the following
dive? 16m for 60 minutes.
a) 2:39 minutes
b) 2:40 minutes
c) 2:42 minutes
d) 2:44 minutes

11) You’re planning a multilevel dive. The first level will be
at 26m for 17 minutes. What is the no decompression
limit for the next level of the dive at 16m?
a) 6 minutes
b) 31 minutes
c) 35 minutes
d) 15 minutes

12) A diver makes three dives in one day. Dive 1: 19m for
30 minutes, surface interval 30 minutes.
Dive 2: 15m for 41 minutes, surface interval 1 hour and
50 minutes. Dive 3: 14m for 55 minutes.
What is the pressure group upon surfacing from the last
dive?
a) U
b) R
c) Y
d) Z

General Skills & Environment

1) In the southern hemisphere the major ocean
currents flow from ______________ on the eastern
seaboard of the land mass and the water is ______.
a) South to North / cold
b) South to North / warm
c) North to South / cold
d) North to South / warm

2) The circulation of major ocean currents is called:
a) the Coriolis Effect
b) longshore drift
c) upwelling
d) wave action

3) Aquatic life injuries may be caused by:
a) fire coral
b) jellyfish
c) stone fish
d) all of the above

4) Tides are caused by the gravitational influence of
the _____ and _____, with the _____ having the
greater effect.
a) moon and wind, moon
b) moon and wind, wind
c) sun and moon, sun
d) sun and moon, moon

5) Most waves are caused by:
a) planetary motion
b) the moon
c) upwelling
d) wind

6) A clenched fist brought toward the chest is a signal
for:
a) I am out of air
b) I am low on air
c) I am low on air and want to share air
d) I am having chest pains

7) Two factors determining the type of pattern used
when conducting an underwater search are the:
a) size and weight of the object
b) weight of the object and bottom composition
c) environmental conditions and size of the object
d) bottom composition and weight of the object

8) When administering one-rescuer CPR, the ratio of
compressions to ventilations is:
a) 30 compressions followed by 2 ventilations
b) 15 compressions followed by 2 ventilations
c) 15 compressions followed by 5 ventilations
d) 30 compressions followed by 5 ventilations

9) Special procedures are required when diving at
altitude because:
a) the partial pressure of nitrogen is increased
since the ambient pressure is increased
b) Dissolved nitrogen would come out of solution
Faster than at sea level
c) the partial pressure of oxygen is increased
d) none of the above

10) A near drowning victim should:
a) be encouraged to see a physician even if they
feel fine
b) be given oxygen if it is available
c) always be treated in a recompression chamber
d) both a and b are correct

11) To correctly perform a Controlled Emergency Swimming
Ascent (CESA) a diver must:
a) keep all equipment in place, look up, reach up,
swim at a normal pace towards the surface while
making a continuous sound and vent excess air
b) swim quickly towards the surface making a
continuous “ahhhhhh” sound
c) drop weights and ascend as slowly as possible
d) look up, reach up and swim quickly towards the
surface

12) It’s recommended that each night diver carry a
minimum of:
a) one primary dive light
b) one primary dive light and one backup light
c) one primary dive light and two backup lights
d) one primary dive light, one backup light and a
chemical light

Equipment

1) When a scuba cylinder is visually inspected the
scuba cylinder is:
a) inspected externally for damage and dents
b) drained of air, has the valve removed and
inspected internally for corrosion
c) inspected for corrosion on the valve threads
d) all of the above

2) The term “open circuit” regulator refers to the fact
that:
a) a malfunction results in a continuous air flow
b) there is no diaphragm in the second stage
c) there is no resistance when breathing
d) exhaled air is released directly into the water

3) The term “fail safe” refers to a regulator’s tendency:
a) to always work properly
b) for a malfunction to result in a continuous air
flow
c) to maintain constant breathing resistance
d) to have an environmentally sealed first stage

4) The purpose of the scuba regulator first and second
stage is to change:
a) ambient pressure to intermediate pressure
to tank pressure
b) tank pressure to intermediate pressure to
ambient pressure
c) tank pressure to intermediate pressure
d) intermediate pressure to absolute pressure

5) When diving at altitudes above 300 metres the use
of a(n) _________ depth gauge will give theoretical
depths rather than actual depth.
a) capillary
b) closed bourdon tube
c) open bourdon tube
d) oil filled

6) A burst disk is a safety device on a scuba tank ____
that vents air if the tank becomes _________
a) neck/ corroded
b) wall / over pressurized
c) valve / over pressurized
d) valve / over heated

7) Which of the following does the dive community
generally agree upon regarding Alternate Air Sources:
a) it must be located in the triangle formed by the
chin and the corners of the rib cage
b) it must be a different colour than the primary
regulator
c) it must come over the diver’s right shoulder
d) all of the above

8) The second stage of a modern scuba regulator will most
likely have either a(n) __________ or _________ valve.
a) downstream / pilot
b) upstream / pilot
c) piston / diaphragm
d) downstream / flutter

9) When diving in extremely cold water, a regulator that
has a(n) _________ may be protected from freezing up
a) environmentally sealed first stage
b) fail safe design
c) downstream valve
d) closed circuit design

10) You should use a lifting device to recover items that
have a minimum weight of ________.
a) 24 kg
b) 18 kg
c) 14 kg
d) 4 kg

11) If water gets inside a steel tank, __________ corrosion
may develop and damage the tank walls.
a) aluminium oxide
b) iron oxide (rust)
c) salt crystal
d) hydrogen

12) General guidelines to follow if a dive computer fails
during a dive are:
a) surface immediately and monitor yourself for
signs of decompression illness
b) Signal to your buddy, ascend, make a safety stop
Wait 12 hrs. or more if using another computer
c) continue the dive at a shallower depth using your
buddy’s dive computer
d) all of the above

Now you have looked at these questions – really recommend you get all the exams to check / revise from to help you pass your PADI IDC / IE.

The fact you have got to the bottom of the page we will assume you have found this a very valuable and helpful resource for your IDC Revision / Studies, therefore, you will be glad to hear that you can buy the full Exam Pack that includes 10 Standards and Dive Theory Mock PADI exams plus a bonus 75 question Pre-IDC Exam paper with answer keys.

Please click the link and BUY all 3 complete IDC revision packs that includes lots of revision documents and 11 practice mock exams, the exams include all the questions and answers you will need to revise to PASS the PADI IDC

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