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
Last Answer : Answer: D
Description : To protect the rotor of a motor disassembled for maintenance or overhaul, it should be ___________________. A. suspended by wire slings in one corner of the shop B. stowed upright on its shaft C. supported by two 'V' notched wood blocks D. returned to the frame as soon as the bearings are removed
Last Answer : Answer: C
Description : The basic type of D.C. motor speed control where a generator armature directly feeds the motor armature and the motor and generator fields are excited by a separate D.C. source is called ___________________. A. Burmeister-Wain B. Ward-Leonard C. Sperry-Rand D. Atlas-Copco
Last Answer : Answer: B
Description : In Fullarton Tachometer, a thin strip with a ______ is attached at one of its ends. (A) mass (B) spring (C) damper (D) shaft
Last Answer : (A) mass
Description : The frequency-response specification of your tape recorder reads within +/ - 3 dB from 150 Hz to 150 kHz at 60 ips. What does this mean?
Last Answer : The recorder can record all frequencies between 150 Hz and 150 kHz at 60 ips without varying the output amplitude more than 3 dB.
Description : Can I replace a 60 watt incandescent light bulb with a fluorescent or LED bulb that puts out more light than the incandescent?
Last Answer : Light output is measured in lumens, and yes, you can find a fluorescent bulb in lumen output equal to or greater than an incandescent 75 or 100 watt bulb.And it won’t be anywhere near 60 watts, so you are safe.
Description : In precision theodolite traverse if included angles are read twice and the mean reading accepted using both verniers having a least count of 30". Assuming the instrument to be in perfect adjustment, linear measurements correct to 6 mm per ... legs) (A) 50" n (B) 30" n (C) 60" n (D) None of these
Last Answer : (A) 50" n
Description : The illustration shows a fluorescent light fixture. The ends of the lamp alternately glow and become dark, but the tube will not light. The most probable cause is that ____________. EL-0081 ... start the lamp D. component 'B' contacts are opening and closing thus prohibiting sufficient current flow
Description : When a fluorescent lamp fails to light, the trouble can be in the _____________. A. lamp B. starter C. ballast D. all of the above
Description : The device shown in the illustration is a/an ____________. EL-0083 A. noise filtering choke B. autotransformer C. fluorescent light ballast D. power factor correction inductor
Description : The diagram shown in the illustration represents a _________. EL-0058 A. dual speed, 2-winding motor controller B. navigation running light circuit C. single phase, 2-motor selectable starter D. common fluorescent lighting circuit
Description : Working of the Fluorescent Tube Light
Last Answer : The fluorescent lamp circuit consists of a choke, a starter, a fluorescent tube and a frame. The length of the commonly used fluorescent tube is 100 cm; its power rating is 40 W ... momentary high voltage surge across the two filaments. Ionization takes place through argon and produces bright light.
Description : When testing for blown fuses in a three-phase supply circuit to a motor, you should first ___________________. A. apply the megger across the tops of the line fuses B. apply an ammeter diagonally across ... of the line fuses D. ensure the circuit is de-energized, and then use a continuity tester
Description : To protect the rotor of a motor disassembled for maintenance or overhaul, it should be ___________________. A. suspended by wire slings in one corner of the shop B. wrapped in several layers of heavy ... flat wood blocks on the workbench D. returned to the frame as soon as the bearings are removed
Description : The kilowatt load can be adjusted on a paralleled generator by using the _____________. A. field rheostat B. governor control C. automatic voltage regulators D. hand tachometer
Description : The small circular symbols to which wire '52N57E' is connected at coordinates '57L' and '57P' shown in the illustration represent ___________________. EL-0100 A. relay contact solder points B. wire wrap connections C. terminal board screws D. switch contact terminals
Description : The meter indicating the position of the 'bridge Thrust lever' shown in the illustration is located ___________________. EL-0095 A. in the Engine Control Room B. on the Bridge C. in the Captain's office D. in the Chief Engineer's office
Last Answer : Answer: A
Description : The diagrams shown in the illustration represent a/an _______________. EL-0093 A. engine order telegraph circuit B. rudder angle indicator arrangement C. engine speed tachometer with repeaters D. sound powered telephone system
Description : An across-the-line starter provides ___________________. A. maximum torque B. slow starting power C. high speed D. reduced voltage
Description : To minimize magnetic field interaction between electrical conductors in physical proximity, it is best to keep them ___________________. A. parallel and as close as possible to each other B. at right angles ... practicable from each other D. at right angles and as far as practicable from each other
Description : In a cartridge-type fuse, the metal element is contained in a ___________________. A. porcelain window B. thermal cut out C. fiber tube D. flasher device
Description : An electric tachometer receives the engine speed signal from a _______________. A. small generator mounted on the engine B. bimetallic sensing device C. stroboscopic sensing device D. vibrating reed meter generating a voltage proportionate to engine speed
Description : When troubleshooting most electronic circuits, 'loading effect' can be minimized by using a voltmeter with a/an ___________________. A. input impedance much greater than the impedance across which the voltage ... sensitivity of less than 1000 ohms/volt D. sensitivity of more than 1000 volts/ohm
Description : An a.c. tachometer is just a ________with one phase excited from the carrier frequency. (A) two-phase A.C. servomotor (B) two-phase induction motor (C) A.C. operated universal motor (D) hybrid stepper motor.
Last Answer : Ans: D This is a special purpose machine whose stator coil can be energized by electronically switched current.
Description : The primary winding of a 220/6 V, 50 Hz transformer is energised from 110 V, 60 Hz supply. The secondary output voltage will be (A) 3.6 V. (B) 2.5 V. (C) 3.0 V. (D) 6.0 V.
Last Answer : (C) 3.0 V.
Description : On some electrical generating equipment one outboard bearing pedestal is insulated from the bedplate. This should be checked with a millivolt meter and a jumper. With the millivolt meter connectd between ... then removed to take a second reading. This eliminates the insulating effect of the bearing.
Description : The reactive power drawn by a motor from an AC generator is the power which is _____________. A. used to establish the magnetic field of the motor B. lost in overcoming friction in the ... by current flow through the windings D. transmitted directly through the rotor shaft to perform useful work
Description : If the supply voltage is 220 volts 60 Hz, what is the operating voltage of the motor controller circuitry illustrated? EL-0011 A. 110 volts DC B. 110 volts AC C. 220 volts DC D. 220 volts AC
Description : In a 60 Hz AC system, the current will pass through one complete cycle in _____________. A. 60 seconds B. 6 seconds C. 1 second D. .016 of a second
Description : A four pole, 60 Hz, three-phase synchronous motor comes up to 1760 RPM when started as an induction motor. What is the percent slip after the rotor field is energized? A. 0 B. 1.1 C. 2.2 D. 3.3
Description : An AC generator produces 60 Hz at 1800 RPM. If the generator speed is increased to 1830 RPM, the cycles will _____________. A. remain at 60 Hz B. increase to 61 Hz C. decrease to 59 Hz D. increase to 63 Hz
Description : If the synchronous speed of a 12 pole, polyphase, induction motor operating at 60 Hz were 600 RPM, how many poles will be required in a similar motor operating at the same frequency but having a synchronous speed of 900 RPM? A. 4 B. 6 C. 8 D. 18
Description : If coils 'R1-R2-R3' at the receiver of figure 'B' shown in the illustration turned opposite of those in the transmitter by design, what corrective action should be taken? EL-0092 A. Reverse the 60 Hz supply ... is needed. C. Interchange leads 'R1' and 'R3'. D. Interchange leads 'R2' and 'R3'.
Description : If the electricity represented by the wave form in 'B' were applied to the left side of the illustrated circuit, the output on the right side would be ____________. EL-0064 A. direct current with the ... lower lead D. clipped to a value equal to the square root of 3 times the input voltage value
Description : When shore power is being connected to a ship in dry dock, _____________. A. the ship's generators are paralleled with the shore power to provide continuous power B. proper phase sequence must be ... 450 volts must be supplied from the shore D. exactly 60 Hz must be provided by the terminal
Description : The standard method of controlling the output voltage of a 440 volt, 60 Hz, AC generator is accomplished by adjusting the ____________. A. prime mover speed droop B. number of poles C. alternator field excitation D. load on the alternator
Description : If coils 'R1-R2-R3' at the receiver of figure 'B' shown in the illustration were in 180 degree error with those of the transmitter, what corrective action should be taken? EL-0092 A. Reverse the 60 Hz ... is proper operation. C. Interchange leads 'R1' and 'R3'. D. Interchange leads 'R2' and 'R3'.
Description : If coil 'R1-R2' at the receiver of figure 'A' shown in the illustration were in 180 degree error with respect to that of the transmitter, what corrective action should be taken? EL-0092 A. No action is ... and 'R2'. C. Interchange connections 'S1' and 'S2'. D. Interchange connections 'S1' and 'S3'.
Description : If coils 'R1-R2-R3' at the receiver of figure 'B' shown in the illustration turned opposite of those in the transmitter, what corrective action should be taken to have both turn in the same direction? EL-0092 A ... is needed. C. Interchange leads 'R1' and 'R3'. D. Interchange leads 'R2' and 'R3'.
Description : If coil 'R1-R2' at the receiver of figure 'A' shown in the illustration turned opposite of that in the transmitter, what corrective action should be taken? EL-0092 A. No action is necessary as this is ... . C. Interchange connections to 'S1' and 'S2'. D. Interchange connections to 'S1' and 'S3'.
Description : The output voltage of a 440 volt, 60 Hz AC generator is controlled by the ______________. A. load on the alternator B. load on the prime mover C. speed of the prime mover D. exciter output voltage
Description : Assuming a standard 60 Hz. input to the circuit shown in the illustration, the ripple frequency would be ____________. EL-0085 A. 30 Hz B. 60 Hz C. 90 Hz D. 120 Hz
Description : Which of the following precautions should be taken when troubleshooting various power circuits using a common solenoid-type mechanical voltage tester (wiggins)? A. Never use this tester on circuits greater ... voltage expected in the circuit in order to prevent damage from an off-scale reading.
Description : Can 60 Hz Transformers be Used at Higher Frequencies?
Last Answer : A: Transformers can be used at fre¬quencies above 50 Hz up through 400 Hz with no limitations provided nameplate voltages are not exceeded. However, 50 Hz transformers will have less voltage ... Where better regulation and smaller physical size are required, contact us for special 400 Hz designs.
Description : Can 60 Hz transformers be operated at 50 Hz?
Last Answer : The transformers rated below 1 KVA can be used on 50 Hz service. Transformers 1 KVA and larger, rated at 60 Hz, should not be used on 50 Hz service, due to the higher losses and resultant heat ... designs are required for this service. However, any 50 Hz transformer will operate on a 60 Hz service.
Description : When reassembling the equipment shown in the illustration, _____________. El-0001 A. item 2A and 2B should not be installed on assembly #2 until assembly #3 or #4 have been secured to assembly ... be secured to assembly #1 to provide support to assembly #2 during the reassembling of the entire unit
Description : What can teachers do to improve reading conditions when their classrooms have only fluorescent lights or no windows?
Last Answer : I found this, @717richboy. I hope it gives you some ideas.
Description : Etched or burned bands on the contact faces of the brushes in a direct current generator can be caused by ____________. A. high mica segments B. copper drag on the commutator C. brushes improperly positioned D. copper embedded in the brushes
Description : Brushes in a generator must be positioned in the neutral plane to avoid sparking between the brushes and the _____________. A. yoke B. armature windings C. field pole windings D. commutator
Description : Handheld phase sequence indicators are useful when ________. A. preparing to parallel alternators B. connecting lighting branch circuits C. troubleshooting DC motors D. connecting shore power lines to the ship