Description : What does the limit switch mechanism senses to operate?
Last Answer : Limit switch mechanism senses whether the open and close travel of the motor has exceeded the limit setting of the motor to operate.
Description : The winch shown in the illustration will not operate in any speed in the lowering direction and at an abnormal speed in 'first point hoist'. The possible cause is that _______________. EL-0102 A. ... '1M' in the power circuit are badly corroded D. master switch contacts 'MS6' have weak springs
Last Answer : Answer: B
Description : If the centrifugal switch or relay used for cutting out the starting winding of a split-phase induction motor fails to open once the motor is in operation, the _____________. A. motor will overspeed B ... C. motor will immediately stall under load D. motor torque will be above normal at rated speed
Description : Explain the operational aspects of limit switch and torque switch in rotork valve actuator.
Last Answer : a. When limit function is selected? b. When torque function is selected? Limit function - when limit function is selected in rotork valve, the limit switches will operate when the limit set ... . The limit switches will not act (only torque switch will act when selected to torque function).
Description : A single-phase induction motor will only start if you spin the rotor rapidly with the line switch closed. After starting, its speed fluctuates between very slow and half-speed. The problem ... in the ________. A. starting winding B. centrifugal mechanism C. centrifugal switch D. running winding
Last Answer : Answer: D
Description : A single-phase induction motor fails to start. The rotor is spun rapidly with the line switch closed. Having started by this method it is noted that the motor fluctuates between a very slow ... lies in the ______ A. starting winding B. centrifugal mechanism C. centrifugal switch D. running winding
Description : To reverse the direction of rotation of a three-phase AC induction motor, do one of the following: w) reverse any two of the three-phase connections x) change the frequency of the applied AC power y) operate the motor below the stall torque at very high slip z) none of the above
Last Answer : ANSWER: W -- REVERSE ANY TWO OF THE THREE-PHASE CONNECTIONS
Last Answer : The damping torque must operate only when the moving system of the indicating instrument is: Actually moving
Description : As shown in the illustration, a 'pitch cutback' feature is incorporated in the system. This circuit reduces pitch amount to prevent engine overload when it senses ____________. EL-0095 A. pitch error of ... servo' C. excessive propeller speed or fuel to either engine D. only one engine on the line
Last Answer : Answer: C
Description : Which component of seed drill is used for transmit power to operate seed dropping mechanism. a) Frame b) Transport wheel c) Seed box d) Covering device
Last Answer : Transport wheel
Description : Why would my multi-speed fan switch operate at reverse strength?
Last Answer : Perhaps in the strange fashion of fans the speed directly after off is the highest, then the rest are respectively slower. And they simply numbered them 0–4 for aesthetic purposes?
Description : What is the difference between a switch and a hub? A. Switches operate at physical layer while hubs operate at data link layer B. Switches operate at data link layer while hubs operate at ... hubs operate at physical layer D. Switches operate at transport layer while hubs operate at physical layer
Last Answer : C. Switches operate at data link layer while hubs operate at physical layer
Description : If the ignition switch is placed in the ON position and all the engine instruments operate properly except the gas gauge, where would the fault probably be?
Last Answer : Between point (3) and the gas gauge tank unit ground.
Description : In accordance with Coast Guard Regulations (46 CFR), a circuit breaker located in the machinery space and installed in a 440V AC system must _____________. A. be dependent upon mechanical ... the maximum asymmetrical shortcircuit current available at the point of application D. all of the above
Description : Which of the following statements is a requirement of Coast Guard Regulations (46 CFR) concerning emergency diesel generator engines? A. The fuel must have a flash point not less than 75°F. B. ... to each side of the vertical. D. The starting battery must produce 12 consecutive cranking cycles.
Description : Coast Guard Regulations (46 CFR), require that an indicating light at the propulsion control station will operate if overloading or overheating occurs in a _______________. A. forced draft blower motor B. steering gear motor C. fuel pump motor D. condensate pump motor
Description : Which of the listed motors will operate at the highest RPM, assuming that each operates at the same frequency? A. A four-pole synchronous motor under normal load. B. A four-pole induction motor under ... A six-pole synchronous motor under normal load. D. A six-pole induction motor under full load.
Last Answer : Answer: A
Description : Universal motors will operate on AC or DC current, and are generally found in _____________. A. portable tools B. large pump motors C. turbo electric main motors D. forced draft fans
Description : A four-pole induction motor, operating on three-phase 60 cycle current will operate at approximately ___________. A. 850 RPM B. 1,150 RPM C. 1,750 RPM D. 3,550 RPM
Description : If the energy input is significantly reduced to the prime mover of one shipboard alternator operating in parallel with others, that alternator will _____________. A. continue to operate at no load B. lose ... overspeed C. begin to motorize and then trip out D. slow down and operate at reduced load
Description : If field excitation is suddenly lost to an alternator operating in parallel, that alternator will _____________. A. supply excessive current to the bus B. operate at the same load, but with reduced voltage C. lose its load and tend to overspeed D. become overloaded and slow down
Description : In the illustrated motor controller circuit, which statment is true? EL-0023 A. The high and low speed lights operate at less than line voltage with a resistor in series. B. This controller can be ... . The wattage of the high speed light must be greater than the wattage of the low speed light.
Description : If there is a reduction in the normally supplied frequency to a 120/240 volt, threephase AC current motor from 60 hertz to 55 hertz, the motor would _____________. A. run at a slower speed B. operate at a lower current C. overheat D. trip off the line
Description : How long after energizing 'ATMX' at '41Y' shown in the illustration do the contacts of 'ATM' operate? EL-0100 A. 3 minutes B. 27 minutes C. 30 minutes D. 33 minutes
Description : If many turns of an alternating current coil for a contactor become short circuited, the coil _____________. A. will continue to operate B. will probably burn out immediately C. will operate on reduced current D. temperature will drop
Description : Modern handheld digital tachometers operate by counting light pulses returned to the unit by ______________. A. the tach generator B. either the coupling or shaft C. a small bulb attached to the shaft D. a piece of reflective tape
Description : Why is it desirable to operate paralleled AC generators at the same power factor? A. Circulating currents are kept to a minimum. B. Field excitation losses are kept to a minimum. C. Generator ... will have a lesser tendency to hunt. D. Because a power factor increase will decrease kilowatt output.
Description : Power necessary to operate the horn relay shown in the illustration ____________. EL-0093 A. comes from each station's magneto B. is supplied from a 115 volt source C. is conducted through the relay's contacts D. also lights lamps 'R' and 'T'
Description : As load is added to a shunt motor, the motor will _________. A. speed up B. continue to operate at the same speed C. slow down slightly D. stop
Description : If many turns of an alternating current coil for a contactor become short circuited, the coil _____________. A. temperature will drop B. will probably burn out immediately C. will continue to operate D. will operate on reduced current
Description : Shunt, series, and compound wound motors, are all DC motors designed to operate from _____________. A. constant potential, variable current DC sources B. variable potential, constant current DC ... C. variable potential, variable current DC sources D. constant potential, constant current DC sources
Description : Power necessary to operate the horn shown in the illustration _____________. EL-0093 A. comes from each station's magneto B. is supplied from a 115 volt source C. is conducted through a relay coil D. also lights lamps 'R' and 'T'
Description : How many different D.C. voltages are required to operate the circuit shown in the illustration? EL-0094 A. Two B. Three C. Four D. Five
Description : On AC vessels, which of the following statements represents the most difficult problem involved in obtaining a DC potential suitable for use by computer components? A. A stepdown transformer is ... voltage must be rectified and made ripple free. D. Rectifiers cannot operate with voltage regulators.
Description : Which type of AC single-phase motor will also operate on direct current? A. Split-phase B. Series-wound C. Shaded-pole D. Repulsion-start
Description : Which of the following statements is true concerning all three-phase alternators? A. Each has three separate but identical armature windings acted on by one system of rotating magnets. B. Each has one ... The three phases always provide power to the load through three sets of slip rings and brushes.
Description : The purpose of the capacitor within component 'B' of the circuit shown in the illustration is to ____________. EL-0081 A. prolong the life of the component's contacts B. discharge the neon within ... the inductive reactance in the circuit D. store power to operate the circuit should 'D' open
Description : Which of the following conditions will occur if the solenoid coil burns out on a cargo winch with an electrical brake? A. The brake will be set by spring force. B. The motor will overspeed and burn ... the cargo boom will fall. D. Nothing will happen; the winch will continue to operate as usual.
Description : Brushless generators are designed to operate without the use of ___________. A. brushes B. slip rings C. commutators D. all of the above
Description : Why do cylindrical Alternators operate with steam turbines?
Last Answer : A: Steam turbines are found to operate at fairly good efficiency only at high speeds. The high speed operation of rotors tends to increase mechanical losses and so the rotors should have a ... axial length are used for Synchronous generators driven by steam turbines with either 2 or 4 poles.
Description : Will rotor earth fault relay operate for earth fault in main exciter winding or RCU Diode Bridge also?
Last Answer : Yes.
Description : How will you proceed to operate the valve manually after an electrical operation?
Last Answer : After electrical operation to operate manually we must tilt the lever provided on the actuator to hand (manual) position by which the sliding clutch gets engaged with hand drive.
Description : Which of the following instruments have least torque/weight ratio: a) Dynamometer type b) PMMC c) Attraction type moving iron d) Repulsion type moving iron
Last Answer : Ans: A
Description : Squirrel cage induction motor has a) Zero starting torque b) Very small starting torque c) Medium starting torque d) Very high starting torque
Last Answer : Ans: B
Description : Which of the following statements describes what will occur if the motor shown in the illustration is required to carry 150% of full load? EL-0056 A. The primary counter emf will be increased. B. ... slip will decrease. D. The slip value, stator current curve, and torque curve will all coincide.
Description : The torque and current curves for a three-phase induction motor with a cage rotor, are shown in the illustration. Which of the following statements is true concerning the depicted curves? EL-0056 A. As slip ... D. If the motor is loaded to the point where 40% slip has resulted, it will stall.
Description : The torque produced by a DC motor armature is the product of the force acting at the armature surface multiplied by _____________. A. work done by the armature in one revolution B. effective ... arm at the center of rotation of the armature D. perpendicular distance to its center of rotation
Description : An increase in the amount of current flow through the armature of a shunt motor is the final result of a/an _____________. A. increase in the load on the motor B. decrease in the load on the motor C. increase in counter EMF D. decrease in armature torque
Description : Which of the following is a characteristic of fractional horsepower repulsion start motors? A. They start with a rotating stator field. B. The short circuiting ring is removed from the commutator while ... brushes are removed from the commutator while starting. D. They have a low starting torque.