Description : An 1.8° step, 4 -phase stepper motor has 40 teeth on 8 poles of the stator. The number of rotor teeth for their rotor will be: (A) 40 (B) 50 (C) 100 (D) 80
Last Answer : An 1.8° step, 4 -phase stepper motor has 40 teeth on 8 poles of the stator. The number of rotor teeth for their rotor will be: 50
Description : A 3 stack stepper motor with 12 number of rotor teeth has a step angle of: (A) 12° (B) 8° (C) 24° (D) 10°
Last Answer : A 3 stack stepper motor with 12 number of rotor teeth has a step angle of: 10°
Description : The disc angle of a good plough varies between a) 25°-30° b) 10°-15° c) 18°-24° d) 42°-45°
Last Answer : 42°-45°
Description : A permanent magnet stepper motor with 8 poles in stator and 6 poles in rotor will have a step angle of (a) 7.5° (b) 15° (c) 30° (d) 60°
Last Answer : d
Description : A 1.8°step, 4-phase stepper motor has a total of 40 teeth on 8 pole of stator. The number of rotor teeth for their rotor will be (A) 40 (B) 50 (C) 100 (D) 80
Last Answer : (B) 50
Description : A retaining wall 6m high supports a backfill with a surcharge angle of 10°. The back of the wall is inclined to the vertical at a positive batter angle of 5°. If the angle of wall friction is 7°, then the resultant ... inclined to the horizontal at an angle of (A) 7° (B) 10° (C) 12° (D) 17
Last Answer : (C) 12°
Description : A three-phase, three-stack, variable reluctance step motor has 20 poles on each rotor and stator stack. The step angle of this step motor is (A) 3o (B) 6o (C) 9o (D) 18o
Last Answer : A three-phase, three-stack, variable reluctance step motor has 20 poles on each rotor and stator stack. The step angle of this step motor is 6o
Description : The air gap in an induction motor should be checked periodically with a feeler gage to detect ____________. A. rotor contact with the laminations B. changes in armature magnetic strength C. excessive bearing wear D. electrical damage to the rotor
Last Answer : Answer: C
Description : The speed of a squirrel-cage induction motor is determined by the ____________. A. diameter of the stator B. number of stator poles C. rotor winding resistance D. rotor conducting bars resistance
Last Answer : Answer: B
Description : Under normal conditions, the speed of a two-speed squirrel cage induction motor is changed by varying the ____________. A. frequency of the applied voltage B. resistance in the rotor circuit C. number of field poles D. amplitude of the applied voltage
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 : A motor using a rheostat in the motor circuit to vary the speed is called a ____________. A. squirrel-cage induction motor B. regenerative braking motor C. wound-rotor induction motor D. synchronous motor
Description : The rotor of a synchronous motor operates in synchronism with the rotating field because ______________. A. of the amortisseur windings B. the rotor is magnetically locked into step with the ... field strength varies directly with rotor slip D. the stator flux rotates in the opposite direction
Description : The purpose of a cage rotor winding placed on the rotor of a synchronous motor is to _____________. A. provide excitation to the DC field B. start the machine as an induction motor C. contribute extra torque at synchronous speed D. prevent the machine from falling out of step
Description : A radio signal moves from air to glass. The angle of incidence is 20°. Calculate the angle of refraction. The relative permittivity of the glass is 7.8. A. 7.8° B. 5.04° C. 6.04° D. 7.04°
Last Answer : D. 7.04°
Description : In standard taper roller bearings, the angle of taper of the outer raceway is (a) 5° (b) 8° (c) 15° (d) 25°
Last Answer : (d) 25°
Description : An aircraft is travelling at 120 kts, what angle of bank would be required for a rate 1(one) turn? a. 30° b. 12° c. 18° d. 35°
Last Answer : c. 18°
Description : The speed of a multi-speed, squirrel-cage, induction motor operating in a fixed frequency system can be changed by _____________. A. reconnecting stator windings for different numbers of poles B. ... sequence of the applied voltage D. reconnecting the stator so that no poles have the same polarity
Last Answer : Answer: A
Description : What Is Stepper Motor. what Is Its Uses?
Last Answer : Stepper motor is the electrical machine which act upon input pulse applied to it. it is one type of synchronous motor which runs in steps in either direction instead of running in complete cycle.so, in automation parts it is used.
Description : The torque, in a _____________is proportional to the square of the armature current (A) DC shunt motor (B) stepper motor (C) 2-phase servomotor (D) DC series motor
Last Answer : (D) DC series motor
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 : A stepper motor is (A) a dc motor. (B) a single-phase ac motor. (C) a multi-phase motor. (D) a two phase motor.
Last Answer : Ans: D Stepper motor works on 1-phase-ON or 2-phase –ON modes of operation
Description : In a stepper motor the angular displacement (A) can be precisely controlled. (B) it cannot be readily interfaced with micro computer based controller. (C) the angular displacement cannot be precisely controlled. (D) it cannot be used for positioning of work tables and tools in NC machines.
Last Answer : (A) can be precisely controlled.
Description : When an AC or a DC motor fails to start, the FIRST step in troubleshooting should be to check the ____________. A. motor windings for obvious opens B. motor controller leads for continuity C. fuse or circuit breaker D. motor controller leads for grounds
Description : On large generators, space heaters are used to ____________. A. keep the machine at ambient tmperature of the machinery space B. maintain rotor and stator winding temperatures above the dew point ... C. prevent condensation in the lube oil D. prevent electrolysis due to condensation in the bearings
Description : Tabling process used for separating two materials of different densities by passing the dilute pulp over a table/deck, which is inclined from the horizontal surface at an angle of about (A) 1 to 2° (B) 2 to 5° (C) 5 to 10° (D) 10 to 15°
Last Answer : (B) 2 to 5°
Description : The helix angle in case of closely coiled helical spring is (A) less than 5° (B) 5° to 7° (C) 7° to 10° (D) more than 10°
Last Answer : (D) more than 10°
Description : The helix angle in case of closely coiled helical spring is (A) less than 10° (B) 10° to 15° (C) 15° to 20° (D) more than 20°
Last Answer : (A) less than 10°
Description : Tilt angle of a disc plough is generally— (A) 10° (B) 15° (C) 20° (D) 45°
Last Answer : (D) 45°
Description : In a right angle bend of a road provided with a transition throughout, the maximum polar angle will be (A) 10° (B) 15° (C) 20° (D) 30°
Last Answer : Answer: Option B
Description : If a Lemniscate curve of transition throughout is introduced to connect two parallel roads, the maximum polar angle of the curve, is (A) 10° (B) 15° (C) 20° (D) 30°
Last Answer : Answer: Option D
Description : A ship strikes the berth generally at an angle (A) 90° with the face of the dock (B) 45° with the face of the dock (C) 30° with the face of the dock (D) 10° with the face of the dock
Last Answer : (D) 10° with the face of the dock
Description : In flat roof of reinforced cement concrete, the recommended angle of slope, is (A) Zero (B) A few degrees (C) 10° (D) 200
Description : The tilt angle varies form…° to….. °. For a good plough a. 20°,30°. c) 15°,30° b. 10°,30°. d) 15°,25°
Last Answer : 15°,25°
Description : If the ailerons are deflected to 10°, compared to 5°, this will cause: a. An increased angle of bank b. An increased rate of roll c. No change to either bank angle or roll rate d. A reduction in the adverse yawing moment
Last Answer : b. An increased rate of roll
Description : What is purpose of Rotor angle limiter?
Last Answer : It limits generator voltage & rotor voltage.
Description : When correcting specific gravity readings of a lead-acid battery for existing temperature conditions, you should ______________. A. add 10 points for each 4° above 80°F B. subtract 10 points for each 4° above 80°F C. add 4 points for each 10° above 80°F D. add 4 points for each 10° below 80°F
Description : The country located between 8° N and 37° N latitudes is (1) Bangladesh(2) India (3) China (4) Pakistan
Last Answer : India
Description : If the residual flux is absent in the rotor iron of the isolated induction generator, a) it will not run. b) it will run as induction motor c) it will burn the winding d) it will not affect the characteristic of the generator
Last Answer : Ans: A
Description : As shown in the illustration, the purpose of the item labeled 'Z', in assembly No. 2, is to _____________. EL-0001 A. keep the rotor in balance B. align the rotor to the stator C. dynamically balance the rotor D. cool the motor
Last Answer : Answer: D
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 : 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 speed of a squirrel-cage, multi-speed, induction motor, as used aboard ship, is varied by changing the __________. A. number of connected poles in the stator B. frequency to the motor C. excitation voltage D. resistance of the rotor circuit
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
Description : What is the rotor speed of a four pole, 60 cycle, induction motor operating at full load with 3% slip? A. 270 RPM B. 540 RPM C. 873 RPM D. 1746 RPM
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
Description : The purpose of the item labeled 'Z' in assembly No. 2, shown in the illustration is to _____________. EL-0001 A. keep the rotor in balance B. align the rotor to the stator C. dynamically balance the rotor D. cool the motor
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 : Discoloration of the rotor bars in a squirrel-cage motor is typical evidence of _____________. A. moisture B. overheating C. vibration D. all of the above