4th Class Power Engineering Practice Questions competency test 101 to 121

Question 101

In an air conditioning duct system, the most effective location for
installing sound absorbing lining is:B
A) near the terminal devices of the ducts.
B) in the suction and discharge plenum of the fan.
C) in the middle section of a run of the duct.
D) 6 m from where a quiet location is required.
E) at the point the duct enters the controlled space.

Question 102

Fins are employed on air conditioning coils to:B
A) decrease the space occupied by the coil in the duct.
B) increase contact surface area between the air stream and the tubes.
C) achieve a lower pressure drop than bare coils would provide.
D) reduce the cost of coil construction.
E) attenuate the noise in the duct.


Question 103

In air conditioning coils, the extended surface provided by fins is called
___________ surface.A
A) secondary
B) primary
C) bare
D) contact
E) tertiary


Question 104

The two types of finned surfaces used on most modern air conditioning coils
are:D
A) spiral finned and extended finned.
B) continued finned and extended finned.
C) flat finned and extended finned.
D) spiral finned and continuous plate finned.
E) flat finned and continuous finned.


Question 105

Coils with a flat finned surface and in-line tubes:D
A) have a greater pressure drop than other types.
B) are normally used for high temperature (hot deck) applications.
C) have higher heat transfer rates than tubes with more closely-spaced fins.
D) are normally used for low temperature cold storage rooms.
E) cause greater air turbulence than other types of coils.


Question 106

In air conditioning systems, coils with rippled fins and a staggered tube
pattern:C
A) have a lower pressure drop than other types.
B) usually have the fins bonded to the tubes using glue.
C) create more turbulence and improve heat transfer efficiency.
D) are normally used for low temperature cold storage rooms.
E) have a much lower first cost compared to other types.


Question 107

Coils with finned surfaces will experience reduced heat transfer efficiency
when the fins are:B
A) crimped
B) poorly bonded to the tubes.
C) closely spaced.
D) exposed to lower temperatures.
E) exposed to higher air flows.


Question 108

The factor that limits the number of fins that can be placed on an air
conditioning coil is the:E
A) temperature of the steam in the coil.
B) temperature of the chilled water in the coil.
C) material of construction of the fin.
D) face velocity of the coil.
E) resistance to air flow.


Question 109

The fin spacing recommended for chilled water air conditioning coils is
__________ fins per inch.A
A) 8 to 14
B) 4 to 15
C) 3 to 8
D) 4 to 8
E) 2 to 4


Question 110

The fin spacing recommended for steam and hot water heating coils is _____
fins per inch.B
A) 8 to 14
B) 4 to 14
C) 3 to 8
D) 4 to 8
E) 2 to 4


Question 111

The fin spacing recommended for direct expansion freezer coils is _____ fins
per inch.C
A) 8 to 14
B) 4 to 14
C) 3 to 8
D) 4 to 8
E) 2 to 4


Question 112

The provisions that must be followed to obtain the proper performance of a
hot water heating coil include:C
1. counter flow arrangement of air and water.
2. connection of water supply at the bottom of the coil.
3. parallel flow direction of air and water.
4. install air vent at the top of the coil.
A) 1, 3 and 4 ONLY
B) 2, 3 and 4 ONLY
C) 1, 2 and 4 ONLY
D) 3 and 4 ONLY
E) 2 and 4 ONLY


Question 113

The reason efficiency is higher for a counter flow versus a parallel air and
water arrangement in a coil is a:A
A) greater mean effective temperature difference.
B) greater fluid velocity within the coil.
C) greater air velocity over the coil.
D) higher turbulence over the coil.
E) greater internal fluid density due to gravity effect.


Question 114

The coil circuiting design that produces a high heat transfer capacity with
a limited water quantity is the _________ design.B
A) single serpentine
B) half serpentine
C) full circuiting
D) double serpentine
E) triple serpentine


Question 115
The air vent(s) for air conditioning coils must be installed at:
A) the highest point of the supply line and return line.E
B) the highest point of the water coils.
C) the highest point of the radiators.
D) the highest point of any vertical loop.
E) all the above locations.


Question 116

For normal heating applications, the required number of rows for a hot water
coil seldom exceeds ______ rows.E
A) 5 to 8
B) 3 to 8
C) 2 to 8
D) 4 to 6
E) 2 to 3


Question 117

For normal cooling applications, the required number of rows for a coil
seldom exceeds ______ rows.B
A) 5 to 8
B) 3 to 8
C) 2 to 8
D) 4 to 6
E) 2 to 3


Question 118

To prevent carryover of moisture into supply ducts, most cooling
applications require the face velocity be kept between:A
A) 2 to 3 m/s.
B) 2 to 4 m/s.
C) 3 to 4 m/s.
D) 2 to 5 m/s.
E) 3 to 6 m/s.


Question 119

Steam coils in air conditioning systems must:
1. constantly eliminate air.D
2. constantly eliminate condensate.
3. constantly eliminate non-condensable gases.
4. maintain a minimum face velocity.
5. achieve a minimum temperature MED.
A) 3 ONLY
B) 2 and 4 ONLY
C) 2, 3, and 5 ONLY
D) 1, 2, and 3 ONLY
E) 1, 3, 4 and 5 ONLY


Question 120

One of the methods used to provide uniform steam distribution to the
individual tubes of a steam coil is:B
A) use larger-diameter tubes.
B) employ an orifice at the supply end of each tube.
C) use perforated tubes.
D) use shorter tubes.
E) use injector nozzles.


Question 121

One of the methods used to provide uniform steam distribution to the
individual tubes of a steam coil is:D
A) use longer tubes.
B) employ an orifice at the outlet of each tube.
C) use perforated tubes.
D) use distributing plates within the steam header.
E) use vacuum breakers.