LICENSE EXAM PREP
What is the most likely cause when a feedwater pump becomes
vapor bound?
a. leaking packing
b. vent left open
c. leaking suction line
d. water too hot
d. water too hot
How is the rotation reversed on a 3 phase motor?
a. reverse the field winding
b. reverse the armature winding
c. reverse both the field and armature winding
d. reverse any two power leads
d. reverse any two power leads
How many watts watts does a 45 hp motor consume operating at
75% efficiency?
a. 25.2
b. 44.8
c. 25,200
d. 44,800
d. 44,800 watts
A circuit breaker serves the same function as a
a. meter
b. resistor
c. fuse
d. solenoid
,c. fuse
Electric current is measured in
a. ohms
b. volts
c. farads
d. amperes
d. amperes
What is the formula for finding the frequency of an alternator?
a. (# of poles x rpm)/120
b. 120/(# of poles x rpm)
c. (120 x # of poles)/rpm
d. 120 x # of poles x rpm
a. (# of poles x rpm)/120
What is the formula for calculating the speed of a synchonous
motor?
a. (# of poles x Hz)/120
b. (120 x frequency)/# of poles
c. (120 x # of poles)/Hz
d. 120 x # of poles x Hz
b. (120 x frequency)/# of poles
Which feedwater system is least efficient?
a. Electric centrifugal pump
b. steam-driven centrifugal pump
c. electric reciprocating pump
d. injector
d. injector
If two centrifugal pumps were connected in parallel, there would
be
a. flow increase, constant pressure
,b. flow decrease, constant pressure
c. constant flow, pressure increase
d. constant flow, pressure decrease
a. flow increase, constant pressure
When starting and motor driven centrifugal pump, the correct
way to put the least amount of strain on the pump and minimum
load on the motor is to have
a. both suction and discharge valves closed
b. both suction and discharge valves open
c. the suction valve open and the discharge valve closed
d. the suction valve closed and the discharge valve open
c. the suction valve open and discharge valve closed
On a steam driven boiler feed pump, which piping is larger?
a. turbine steam inlet and pump discharge
b. turbine steam inlet and pump suction
c. turbine steam exhaust and pump discharge
d. turbine steam exhaust and pump suction
d. turbine steam exhaust and pump suction
Why are staybolts drilled?
The leak if the bolt fails
What does the economizer heat?
Feedwater
A ______ fuse is necessary for a circuit with a load of 21,000 watts
and a voltage of 220 volts.
A. 100
, B. 150
C. 175
D. 200
A. 100 amps. Note: V = IR Therefore I = V/R 21,000 amps /220 volts
= 95 amps
At 0 psig, how many BTU's are required to change 1 lb of water
at 212F to steam?
A. 144
B. 180
C. 970
D. 1190
C. 970 BTU
Radiation is:
A. the movement of liquids or gases created by a temperature
difference.
B. Heat transfer by direct molecular contact
C. the weight of a substance compared to unity
D. Heat transfer by waves
D. Heat transfer by waves
Sensible heat is:
A. An established relationship comparing any substance to the
heat content of water.
B. Heat quantity that can be felt or measured by a thermometer
C. Heat quantity above the saturation point
D. Measure of heat intensity
B. Heat quantity that can be felt or measured by a thermometer
All steam lines should be pitched:
A. In the direction of flow
B. Back towards the boiler