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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Textbook Question
Chapter 33, Problem 15RQ
The most common type of pump used for hydronic heating systems is the
A. reciprocating.
B. pulsating.
C. scroll.
D. centrifugal.
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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 33 Solutions
Refrigeration and Air Conditioning Technology (MindTap Course List)
Ch. 33 - A hydronic heating system uses ______to move heat...Ch. 33 - Describe a zone in a hydronic heating system.Ch. 33 - Name four sources of heat commonly used for...Ch. 33 - Give three reasons that air is detrimental to a...Ch. 33 - Explain the difference between a wet-base and a...Ch. 33 - Where is air vented from a hydronic heating...Ch. 33 - The "point of no pressure change" is located at...Ch. 33 - The purpose of a limit control in a boiler is to...Ch. 33 - The device that relieves the pressure in a boiler...Ch. 33 - Describe the function of a low-water cutoff.
Ch. 33 - The relief valve setting for a typical...Ch. 33 - Describe how an air cushion tank functions in a...Ch. 33 - True or False: City water does not contain air.Ch. 33 - State two ways that air can get into a hydronic...Ch. 33 - The most common type of pump used for hydronic...Ch. 33 - Another term for pump pressure is feet of _______.Ch. 33 - Two types of zone control valves are the _____and...Ch. 33 - Why must expansion be considered when sizing...Ch. 33 - How is expansion in hot water pipes handled?Ch. 33 - Sketch the following systems: one pipe, two-pipe...Ch. 33 - Describe the advantage of a two-pipe...Ch. 33 - The pressure differential bypass valve is most...Ch. 33 - What is the heat output, in Btu/h, of a terminal...Ch. 33 - In a primary-secondary pumping arrangement, the...Ch. 33 - The temperature of the water at the outlet of a...Ch. 33 - A tankless water-heating system gets its heat from...Ch. 33 - How much of the sun's energy actually reaches the...Ch. 33 - The varying intensity of the sun's energy that...Ch. 33 - Drain-down systems would best be used in which...Ch. 33 - Why are solar systems intended to be used as a...
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