Past Exam Questions and Correct Answers/ Latest
Stationary Engineer Electric Exam Review 2026-2027
Assume that a switchboard ammeter which is connected to a current transformer is
damaged and must be removed without interrupting the service. Of the following,
an ESSENTIAL precaution to be taken before disconnecting the ammeter is to -
ANSWER-short the secondary of the transformer
A DC relay is rated at 6 volts and 120 ohms. This relay can be operated from a 120
volt line by connecting a ___________ ohm resistance in __________ with relay -
ANSWER-2280: series
Some relays are provided with dash-pots. The FUNCTION of these dash-pots is to
provide - ANSWER-delayed time action
An ammeter has a full scale deflection for a current of 0.01 amperes and an
internal resistance of 20 ohms. In order to have the ammeter read full-scale for a
current of 10 amperes and not damage its movement, a shunt should be used
having a value of__________ ohms. - ANSWER-0.02
An air circuit breaker has contacts that flash. The MOST probable cause of this
trouble is that the - ANSWER-barriers are broken
The MAIN purpose of a shunt trip on a circuit breaker is to - ANSWER-permit the
breaker to be opened electrically from a remote location, regardless of load
conditions at the breaker
The grid-controlled gas-type electronic tube MOST often used in motor control
circuits is the - ANSWER-thyratron
1
,Under normal atmospheric conditions, a pressure gauge that reads 24 inches of
mercury is indicating an absolute pressure of MOST NEARLY_____________
P.S.I. - ANSWER-26.5
The PRIMARY function of a hydrometer is to measure the rate of - ANSWER-
relative humidity
A venturi meter is used to measure the rate of - ANSWER-fluid flow
The PRINCIPLE thickening agent used in lubricating greases is - ANSWER-
metallic soap
The specific gravity of liquid is USUALLY determined by means of a -
ANSWER-hydrometer
The pull required on the fall line (negating friction) to hoist a 120 pounds weight,
using a four-part block and tackle, is ___________ lbs. - ANSWER-30
Of the following terms, the one which does NOT describe a way of finishing the
ends of a rope is the - ANSWER-bight
When hoisting a load by means of sling, the stress in each leg of the sling will -
ANSWER-increase as the angle between the horizontal and the sling leg decreases
The MAXIMUM pressure in an upright cylinder 6 feet in diameter, 8 feet high,
and open at the top, when filled tot he brim with water, is MOSTLY NEARLY
______________ lbs/sq.ft. - ANSWER-500
2
,The MAXIMUM height to which water can be lifted by means of suction alone, at
sea level, is APPROXIMATELY _____________ feet. - ANSWER-34
The TOTAL number of 4 inch diameter pipe that is required to equal the water
flow capacity of an 8 inch diameter pipe (negating friction) is - ANSWER-4
The number of threads, per inch, on the standard machine screw MOST suitable
for general use is - ANSWER-32
The friction losses which occur when water flows through a pipe vary MOST
NEARLY _____________ with the ____________. - ANSWER-directly; velocity
squared
Small by-pass lines are sometimes furnished around large gate valves MAINLY to
- ANSWER-balance the pressure on the gate when the valve is being opened
The sudden surge caused by an abrupt change in the speed of the pumps in a closed
liquid piping system is USUALLY called - ANSWER-water hammer
The valve that permits water to flow one direction only is the ____________ valve
- ANSWER-check
Most flanged butterfly valves can be brought from a fully closed position to a fully
opened position in _____________ turn(s). - ANSWER-a quarter
The efficiency of two centrifugal pumps operating in parallel is ___________ of
one of the pumps operating alone. - ANSWER-practically the same as that
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, Assume that a spur gear having 20 teeth revolves at 80 r.p.m and drives another
super gear having 40 teeth. The speed at which the gear having 40 teeth revolves is
_____________ r.p.m. - ANSWER-40
A centrifugal pump has a plain flat-joint seal between the impeller and the casting.
If the clearance of the seal become enlarged due to wear, thereby reducing the
pump's efficiency, it would be GOOD practice to - ANSWER-renew the impeller
The one of the following statement which CORRECTLY describes a speed
characteristic for a centrifugal pump under normal operating conditions is: -
ANSWER-Total head varies directly with the square of the speed
The MAIN function of a pump stuffing box is to - ANSWER-protect the pump
against leakage at the point where the shaft passes through the pump casting
The PROPER order of the event that takes place in a stroke internal combustion
engine - ANSWER-Air intake, compression, power expansion, and exhaust
The number of cycles in an internal combustion engine is AT LEAST
____________ cycles. - ANSWER-two
The lumens per watt taken by a lamp varies with the types and size
of lamp. Given that one candlepower light source emits 12.57 lumens, the lumens
per watt taken by a 75 candlepower lamp drawing 40 watts is APPROXIMATELY
- ANSWER-23.6
A 230 volt, 25 cycle magnetic brake coil to be rewound to operate properly on 60
cycles at the same voltage. Assuming that the coil 25 cycles has 1800 turns, at 60
cycles the number of turns should be - ANSWER-reduced to 750
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