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 : Moisture accumulating in electric motors and generator windings having a cold insulation resistance greater than 50,000 ohms may be baked out with internal heat. This heat can be developed by ____________. ... an electric welder and feeding it into the armature while running the motor at full speed
Last Answer : Answer: A
Last Answer : In a capacitor start motor, the phase displacement between starting and running winding can be nearly 90°.
Description : The ratio of average values of shear stresses produced on the bed and the banks of a channel due to flowing water is (A) Less than 1 (B) Equal to 1 (C) Greater than 1 (D) Equal to zero
Last Answer : Answer: Option C
Description : What precaution should be taken with a vessel's impressed current cathodic protection system after a drydocking period during which the hull has been painted? A. Output currents should be carefully monitored ... slight (10-15%) overcurrent to the anodes should be allowed in order to speed drying.
Last Answer : Answer: C
Description : In a thyristor Latching current is ________ than Holding current a) Equal b) Less c) Greater d) None
Last Answer : Ans: Greater
Description : A salient pole synchronous motor is running at no load. Its field current is switched off. The motor will (A) come to stop. (B) continue to run at synchronous speed. (C) continue to run at ... more than the synchronous speed. (D) continue to run at a speed slightly less than the synchronous speed.
Last Answer : (B) continue to run at synchronous speed.
Description : A single-phase induction motor starts, comes up to about 75% rated speed, slows down to a lower speed, and accelerates again. The problem is most likely in the ____________. A. starting winding B. running winding C. starting capacitor D. running centrifugal switch
Last Answer : Answer: B
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 : 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 : The main purpose of the auxiliary winding on a split-phase, single-phase motor is to _____________. A. limit the starting voltage B. increase the starting current C. start the motor D. keep the motor running in the event the main winding should fail
Description : In a cup, tea cools from 90°C to 80°C in exactly one minute. It will cool from 70°C to 60°C in (a) less than one minute (b) exactly one minute (c) nearly one minute (d) more than one minute
Last Answer : Ans:(d)
Description : Light from the Sun reaches us in nearly (1) 8 min (2) 2 min (3) 6 min (4) 4 min
Last Answer : (1) 8 min Explanation: The sun's light takes about 8 minutes to reach the Earth after it has been emitted from the sun's surface. The time it takes for light to reach planets in our Solar System varies from about 3 minutes for Mercury, to about 5.3 hours for Pluto.
Description : Light from the Sun reaches us in nearly (1) 2 minutes (2) 4 minutes (3) 8 minutes (4) 16 minutes
Last Answer : (3) 8 minutes Explanation: The sun's light takes about 8 minutes to reach the Earth after it has been emitted from the sun's surface. The time it takes for light to reach planets in our Solar System ... Way, which is our galaxy) varies from about 3 minutes for Mercury, to about 5.3 hours for Pluto
Last Answer : (3) 8 minutes Explanation: The sun's light takes about 8 minutes to reach the Earth after it has been emitted from the sun's surface. The time it takes for light to reach planets in our Solar System ... Way, which is our galaxy) varies from about 3 minutes for Mercury, to about 5.3 hours for Pluto.
Last Answer : 8 min
Description : Reduced voltage applied to a motor during the starting period will _____________. A. result in decreased acceleration time only B. lower the starting current and increase accelerating time C. cause a greater starting torque D. increase the starting current and pump capacity
Description : The rotor slots of a repulsion-type motor are generally skewed (placed nonparallel to the rotor axis) to _________. A. produce a constant starting torque B. permit a greater air gap with the starter C. permit a smaller air gap with the starter D. reduce eddy current losses
Description : Under ideal conditions, the collector current is (a) Equal to base current (b) Nearly equal to emitter current (c) Less than base current (d) always zero
Last Answer : (b) Nearly equal to emitter current
Description : For a balanced section, the tensile stress in the reinforcement [ A ] reaches its allowable stress [ B ] is always less than its allowable stress [ C ] may be greater than its allowable stress [ D ] none of the above
Last Answer : [ A ] reaches its allowable stress
Description : The function of the commutator in a DC motor is to ________. A. reverse the flow of current through the armature B. reverse the flow of current in the field poles C. reduce the reluctance of the magnetic path through the motor D. shift the neutral running plane of the brushes to prevent sparking
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 : In a diesel electric plant, raising the generator's field excitation will cause the DC propulsion motor to ________. A. increase in speed B. decrease in speed C. affect generator speed only D. affect main motor speed if done in conjunction with higher generator engine speeds
Description : A dc series motor driving and electric train faces a constant power load. It is running at rated speed and rated voltage. If the speed has to be brought down to 0.25 p.u. the supply voltage has to be approximately brought down to (A) 0.75 p.u (B) 0.5 p.u (C) 0.25 p.u (D) 0.125 p.u
Last Answer : A dc series motor driving and electric train faces a constant power load. It is running at rated speed and rated voltage. If the speed has to be brought down to 0.25 p.u. the supply voltage has to be approximately brought down to 0.5 p.u
Description : In the illustration, moving the engine room reference in the direction indicated will _________. SE-0002 A. cause a positive signal to be sent to the ahead function generator creating a more ... the ahead valve to open until the negative signal exceeds the low lube oil pressure override signal
Description : If a car starting from rest reaches a velocity of 18 m s-1 after 6.0 s then its acceleration is A. 1 m s-2 B. 2 m s-2 C. 3 m s-2 D. 4 m s-2
Last Answer : 3 m s-2
Description : The torque-speed characteristics of an a.c. operated universal motor has a ______characteristic and it______ be started under no-load condition. (A) inverse, can (B) nearly inverse, can (C) inverse, cannot (D) nearly inverse, cannot
Last Answer : Ans: C If torque is zero then speed may exceed up to infinite, that is dangerous for machine and machine can be damaged. N α 1/ T
Description : If an induction motor were to be operated at 90% rated voltage, _____________. A. there would be an increase in starting torque B. starting current would increase slightly C. synchronous speed would decrease slightly D. the slip would increase
Description : A flywheel on a motor goes from rest to 1000 rpm in 6 sec. The number of revolutions made is nearly equal to (A) 25 (B) 50 (C) 100 (D) 250
Last Answer : (B) 50
Description : Which of the conditions listed will indicate the need to clean the insulation on the windings of an electric motor? A. Higher than normal operating temperature. B. Excessive vibration at normal speed. C. Sparking at the brushes. D. High megger readings.
Description : In a 15 HP induction-type motor with a cage rotor, the current required at standstill to produce starting torque is approximately ____________. A. half the full load current B. equal to the full load current C. five times the full load current D. ten to twenty times the full load current
Description : The synchronous speed of an induction motor is the ________. A. speed at which the rotor turns B. speed of the rotating field C. frequency of the rotor current D. slip in per cent of rotor RPM
Description : How do know when electric current is flowing in a light bulb circuit?
Last Answer : The bulb glows indicating that there is current flow. If thereis any ammeter in the circuit, it reads when there is current flowin the circuit
Description : How do you know when electric current is flowing in a light bulb circuit?
Last Answer : Need answer
Description : Calculate the power of a material with electric field 100 units at a distance of 10cm with a current of 2A flowing through it. a) 10 b) 20 c) 40 d) 80
Last Answer : b) 20
Description : Which of the following is not a characteristic of organic compounds? (a) They usually have low melting points. (b) They usually are only slightly soluble or insoluble in water. (c) If water ... they seldom conduct an electric current. (d) Bonds which bind the atoms together are nearly always ionic.
Last Answer : Bonds which bind the atoms together are nearly always ionic.
Description : When a synchronous motor is running at synchronous speed, the damper winding produces (A) damping torque. (B) eddy current torque. (C) torque aiding the developed torque. (D) no torque.
Last Answer : (D) no torque.
Description : Starting from point A, Ajit walks 14 metres towards west, he then turns to his right and walks 14 metres and then turns to his left and walks 10 metres. He again turns to his left and walks 14 metres and reaches to the point E. The shortest distance between A and E is (A) 38 (B) 42 (C) 52 (D) 24
Description : The magnitude of the quarks' electric charge is: w) zero. x) greater than the electron's charge. y) equal to the electron's charge. z) less than the electron's charge.
Last Answer : ANSWER: Z -- LESS THAN THE ELECTRON'S CHARGE.
Description : The insulation resistance of electric equipment and machinery should be tested for the lowest normal insulation values _____________. A. immediately after shutting down the machine B. every time the brush rigging is ... starting up the machine D. every 30 days whether the machine is in use or not
Description : Erosion and pits formation on the impeller of a centrifugal pump may be due to (A) Cavitation (B) Low speed of impeller (C) Its operation with delivery valve closed for considerable time after starting the pump (D) Off centering of pump with motor
Last Answer : (A) Cavitation
Description : The company’s negotiation starting position for wages a. is never more than 150% of the current contract. b. is always lower than what Labor expects. c. is always exactly 80% of the current contract. d. is always half of the increase workers are asking for. e. none of these.
Last Answer : a. is never more than 150% of the current contract.
Description : An electric immersion heater of `1.08 kW` is immersed in water . After it has reaches a temperature of `100^(@)C` , how much time will be required to
Last Answer : An electric immersion heater of `1.08 kW` is immersed in water . After it has reaches a temperature of `100^(@)C` ... 50 s B. 420 s C. 105 s D. 105 s
Description : If the depth of actual neutral axis is greater than the depth of critical neutral axis, then [ A ] Concrete attains its permissible stress earlier [ B ] Steel attains its permissible stress earlier [ C ] Both concrete and steel reaches its permissible stresses simultaneously [ D ] None of the above
Last Answer : [ A ] Concrete attains its permissible stress earlier
Description : In the ________ algorithm of TCP, the size of the congestion window increases exponentially until it reaches a threshold A. slow-start B. congestion avoidance C. congestion detection D. none of the above
Last Answer : A. slow-start
Description : Assertion : If a current is flowing through a conducting wire of non-uniform cross-section, drift speed and resistance both will increase at a section
Last Answer : Assertion : If a current is flowing through a conducting wire of non-uniform cross-section, drift ... . If Assertion is false but Reason is true.
Description : A low-voltage protection circuit is used in electric motor starting equipment to _____________. A. trip circuit contactors when the motor overspeeds due to low voltage B. trip circuit ... voltage without manually resetting D. prevent the motor from restarting automatically on restoration of voltage
Description : A fireman is running to get a net under a lady who looks like she might jump off the balcony of her 20 story apartment building. There is nothing below her except a 20 story fall. The fireman is still ... get there in time. The woman is not hurt more than a bruise. How is that possible? -Riddles
Last Answer : She fell back into her apartment, jumping from the balcony into the inside.
Description : The amount of current flowing through a circuit with a 40 V source and 6.8 kΩ of resistance is equal to: A. 27.2 mA B. 59 mA C. 5.9 mA D. 590 mA
Last Answer : The amount of current flowing through a circuit with a 40 V source and 6.8 kΩ of resistance is equal to: 5.9 mA
Description : On a clear night, we can see nearly ________ stars with naked eyes. (a) 3,000 (b) 10,000 (c) 30,000 (d) 100,000
Last Answer : Ans:(a) Miscellaneous