Refrigeration and Air Conditioning Technology (MindTap Course List)
8th Edition
ISBN: 9781305578296
Author: John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson
Publisher: Cengage Learning
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Chapter 41, Problem 8RQ
When the outside ambient air temperature is 90°F, the temperature of the condensing refrigerant in a standard- efficiency unit should be approximately
A. 120°F.
B. 130°F.
C. 140°F.
D. 150°F.
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3.
9.
10.
The centrifugal tension in belts
(a) increases power transmitted
(b) decreases power transmitted
(c) have no effect on the power transmitted
(d) increases power transmitted upto a certain speed and then decreases
When the belt is stationary, it is subjected to some tension, known as initial tension. The value of this
tension is equal to the
(a) tension in the tight side of the belt
(b) tension in the slack side of the belt
(c) sum of the tensions in the tight side and slack side of the belt
(d) average tension of the tight side and slack side of the belt
The relation between the pitch of the chain (p) and pitch circle diameter of the sprocket (d) is given by
60°
(a) p=d sin
(c) p=d sin
(120°
T
where T Number of teeth on the sprocket.
90°
(b) p=d sin
T
180°
(d) p=d sin
T
OBJECTIVE TYPE QUESTIONS
1.
The maximum fluctuation of energy is the
2.
(a) sum of maximum and minimum energies
(b) difference between the maximum and minimum energies
(c) ratio of the maximum energy and minimum energy
(d) ratio of the mean resisting torque to the work done per cycle
In a turning moment diagram, the variations of energy above and below the mean resisting torque line
is called
(a) fluctuation of energy
(b) maximum fluctuation of energy
(c) coefficient of fluctuation of energy
(d) none of the above
Chapter 16: Turning Moment Diagrams and Flywheel 611
The ratio of the maximum fluctuation of speed to the mean speed is called
3.
(a) fluctuation of speed
(c) coefficient of fluctuation of speed
4.
(b) maximum fluctuation of speed
(a) none of these
The ratio of the maximum fluctuation of energy to the.......... is called coefficient of fluctuation of
energy.
(a) minimum fluctuation of energy
(b) work done per cycle
The maximum fluctuation of energy in a flywheel is equal to
5.…
OBJECTIVE TYPE QUESTIONS
1.
The velocity ratio of two pulleys connected by an open belt or crossed belt is
2.
(a) directly proportional to their diameters
(b) inversely proportional to their diameters
(c) directly proportional to the square of their diameters
(d) inversely proportional to the square of their diameters
Two pulleys of diameters d, and d, and at distance x apart are connected by means of an open belt
drive. The length of the belt is
(a)(d+d₁)+2x+
(d₁+d₂)²
4x
(b)(d₁-d₂)+2x+
(d₁-d₂)²
4x
(c)(d₁+d₂)+ +2x+
(d₁-d₂)²
4x
(d)(d-d₂)+2x+
(d₁ +d₂)²
4x
3.
In a cone pulley, if the sum of radii of the pulleys on the driving and driven shafts is constant, then
(a) open belt drive is recommended
(b) cross belt drive is recommended
(c) both open belt drive and cross belt drive are recommended
(d) the drive is recommended depending upon the torque transmitted
Due to slip of the belt, the velocity ratio of the belt drive
4.
(a) decreases
5.
(b) increases
(c) does not change
When two pulleys…
Chapter 41 Solutions
Refrigeration and Air Conditioning Technology (MindTap Course List)
Ch. 41 - Before installing a gauge on the high-pressure...Ch. 41 - Capacitors should be shorted with a(n)...Ch. 41 - The high- and low-side pressures on an operating...Ch. 41 - Why do most air-conditioning systems not need a...Ch. 41 - A typical standard-efficiency evaporator under...Ch. 41 - The typical temperature difference between the...Ch. 41 - When the ambient outside air temperature isand the...Ch. 41 - When the outside ambient air temperature is 90F,...Ch. 41 - If a condensing pressure is 260 psig for R-22,...Ch. 41 - How is high efficiency accomplished in an...
Ch. 41 - True or False: When troubleshooting a small...Ch. 41 - The suction gas may have a high superheat if the...Ch. 41 - If the suction pressure is low and the suction...Ch. 41 - What electrical test instrument is used to measure...Ch. 41 - What electrical test instrument is used to measure...Ch. 41 - Most condensers will subcool the refrigerant to...Ch. 41 - What are two types of fixed-bore metering devices?Ch. 41 - It no crankcase heat is at the compressor, what...Ch. 41 - What is the purpose of the internal overload...Ch. 41 - If a condenser circuit breaker is tripped, you...
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