1 Answer

Answer :

In motor circuit static frequency changers are used for speed regulation.

Related questions

Description : When did Fluther get started? Any major milestones and game changers since the beginning?

Last Answer : Welcome to Fluther. I believe it started in 2007. I've been here since the end of 2009. It was a large-ish site. What set it apart was the rule requiring high writing standards. Also, we ... us their questions, and the community will do its best to try to get accurate information. Enjoy yourself.

Description : Will I find any used tire changers on Craig's List?

Last Answer : You can find umpteen used tire changers on Craig's List. You will be surprised to see the number of items that appear when you search, with the used tire changers appearing in Craig's list of most cities ... on the website and sign up for an account and type in used tire changers on the search box.

Description : are cd changers durable?

Last Answer : Most CD changers are very durable, and handle very well even on rough, bumpy roads.

Description : Do all CD changers play MP3s, or do I need special ones?

Last Answer : All current CD changers can play mp3 files taht are recorded on CD

Description : Which car CD changers come with remote controls?

Last Answer : The Clarion FMC250 has a remote control option available.

Description : What car cd changers come with a remote?

Last Answer : The Pioneer AVH-P4100 and the Jensen VM9312HD are both excellent car stereos with changes and remotes.

Description : Why the tap changers are always connected to HV side of the transformer? 

Last Answer : During tap changing action the load current has to be shifted from one tap to another tap. In case HV wining the load current will be less. Hence lesser arcing will take place. 

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

Last Answer : Answer: A

Description : The variable resistance placed in the rotor circuit of a wound-rotor induction motor provides for __________. A. speed control B. frequency control C. voltage control D. use as a split-phase motor

Last Answer : Answer: A

Description : A single degree of freedom spring-mass system is subjected to a harmonic force of constant amplitude. For an excitation frequency of √3k/m , the ratio of the amplitude of steady state response to the static deflection of the spring is __________ A. 0.2 B. 0.5 C. 0.8 D. None of the above

Last Answer : B. 0.5

Description : If a single-phase induction motor fails to start, the problem may be _____________. A. an open in the main winding B. a shorted shunt field C. a closed centrifugal switch D. low circuit frequency

Last Answer : Answer: A

Description : If an electric motor fails to start, you should FIRST check the _____________. A. phase sequence B. ampere load C. fuse or circuit breaker D. line frequency

Last Answer : Answer: C

Description : If a single-phase induction motor fails to start, the problem may be _____________. A. an open in the run winding B. a shorted shunt field C. a closed centrifugal switch D. low circuit frequency

Last Answer : Answer: A

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

Last Answer : Answer: C

Description : In static Kramer drive, motor turns ratio is 0.6, the firing angle is 120o. The motor slip is   (a) 0.633 (b) 0.533 (c) 0.833 (d) 0.733 

Last Answer : In static Kramer drive, motor turns ratio is 0.6, the firing angle is 120o. The motor slip is 0.833

Description : The full load torque of an electric motor is the __________. A. minimum torque developed by the motor accelerating from stop to full speed B. turning moment exerted by the motor at rated load ... and frequency D. turning moment exerted by the motor from any rotor angular position at any load

Last Answer : Answer: B

Description : Which of the following module of FEA is used to determine natural frequency? a.Static analysis b.Thermal analysis c.Modal analysis d.All of the above

Last Answer : c.Modal analysis

Description : What is static frequency converter?

Last Answer : Static Frequency converter is a static device with powerelectronic component such as scrs etc

Description : The static deflection of a spring under gravity, when a mass of 1 kg is suspended from it, is 1 mm. Assume the acceleration due to gravity g = 10 m/s^2. The natural frequency of this spring-mass system (in rad/s) is A 100 B 150 C 200 D 250

Last Answer : A 100

Description : Calculate the static deflection in μm of transverse vibrations if the frequency is 200Hz. A. 6.21 B. 0.621 C. 62.1 D. 0.006

Last Answer : A. 6.21

Description : A weight of 50 N is suspended from a spring of stiffness 4000N/m and subjected to a harmonic force of magnitude 60N and frequency 60 Hz. what will be the static displacement of the spring due to maximum applied force A. 0.015m B. 0.15 m C. 15 m D. 150m

Last Answer : B. 0.15 m

Description : Calculate coefficient of viscous damper, if the system is critically damped. Consider the following data: 1. Mass of spring mass damper system = 350 kg 2. Static deflection = 2 x 10 -3 m 3. Natural frequency of the system = 60 rad/sec ... /m B. 80 x 10 3 N-s/m C. 42 x 10 3 N-s/m D. None of the above

Last Answer : C. 42 x 10 3 N-s/m

Description : Calculate coefficient of viscous damper, if the system is critically damped. Consider the following data: 1. Mass of spring mass damper system = 350 kg 2. Static deflection = 2 x 10 -3 m 3. Natural frequency of the system = 60 rad/sec ... /m b. 80 x 10 3 N-s/m c. 42 x 10 3 N-s/m d. None of the above

Last Answer : c. 42 x 10 3 N-s/m

Description : Calculate the static deflection in μm of transverse vibrations if the frequency is 200Hz. a) 6 b) 0.6 c) 60 d) 0.006

Last Answer : a) 6

Description : Calculate the natural frequency of transverse vibrations if the static deflection is 0.01mm. a) 157.6 b) 144.8 c) 173.2 d) 154.1

Last Answer : a) 157.6

Description : Static deflection and frequency are independent of each other. a) True b) False

Last Answer : b) False

Description : A series wound DC motor has its armature and field connected in series with a resistor. When the motor is disconnected from its power supply, this motor will exemplify __________. A. the ... the proper connections for an automatic strip heater C. a reversing controller circuit D. dynamic braking

Last Answer : Answer: D

Description : Explain working of static AC circuit breaker. 

Last Answer : Static AC Circuit breaker: The circuit configuration of static AC circuit breaker using SCR is shown in the figure. When switch S' is closed, the SCRs T1 and T2 are fired in positive ... non-availability of gate current. Thus the maximum time delay for breaking the circuit is one half-cycle.

Description :  In a variable speed induction motor derive V/f kept constant over a wide range of its frequency variation. The motor operates in the following mode : -  a) Constant power mode b) Constant torque mode c) Constant slip mode d) Variable power and variable torque mode

Last Answer :  In a variable speed induction motor derive V/f kept constant over a wide range of its frequency variation. The motor operates in the following mode : - Constant torque mode

Last Answer : When the frequency of the rotor of an induction motor is small, it can be measured by d.c. moving coil milli-voltmeter

Description : Draw the power and control circuit diagram for forward — stop — Reverse type DOL starter for 3 phase induction motor.

Last Answer : Draw the power and control circuit diagram for forward — stop — Reverse type DOL starter for 3 phase induction motor.

Description : Describe the power and control circuit for automatic Star-Delta starter for 3-phase induction motor.

Last Answer : Power circuit: Control circuit: 

Description : Draw power and control circuit for simple plugging of induction motor.

Last Answer : Fig. Power and control circuit for simple plugging of induction motor.

Description : A centre zero ammeters connected in the rotor circuit of a 6-pole 50 Hz induction motor makes 30 oscillations in one minute. The rotor speed is

Last Answer : A centre zero ammeters connected in the rotor circuit of a 6-pole 50 Hz induction motor makes 30 oscillations in one minute. The rotor speed is 990.

Description : In a series R-C circuit, with the increase in frequency, current (A) Reduces (B) Increases (C) Does not change (D) Becomes zero

Last Answer : In a series R-C circuit, with the increase in frequency, current Increases

Description : A series R-L-C Circuit has a resonant frequency of 1000 Hz. If the values of R, L and C are doubled, the new resonant frequency is

Last Answer : A series R-L-C Circuit has a resonant frequency of 1000 Hz. If the values of R, L and C are doubled, the new resonant frequency is 500 Hz

Description : In a series RLC circuit that is operating above the resonant frequency, the current : -  a) lags the applied voltage b) leads the applied voltage c) is in phase with the applied voltage d) is zero

Last Answer : In a series RLC circuit that is operating above the resonant frequency, the current : - lags the applied voltage

Description : In a pure capacitive circuit if the supply frequency is reduced to 1/2, the current will?

Last Answer : In a pure capacitive circuit if the supply frequency is reduced to 1/2, the current will be reduced by half.

Description : In a pure inductive circuit if the supply frequency is reduced to 1/2, the current will?

Last Answer : In a pure inductive circuit if the supply frequency is reduced to 1/2, the current will be doubled.

Description : In a series L-C circuit at the resonant frequency the?

Last Answer : In a series L-C circuit at the resonant frequency the current is maximum.

Description : In R-L-C series resonant circuit magnitude of resonance frequency can be changed by changing the value of?

Last Answer : In R-L-C series resonant circuit magnitude of resonance frequency can be changed by changing the value of L or C.

Description : Before servicing the device indicated as 'A' in panels #1 and #3 of the illustration, the device labeled 'CT' must __________. EL-0003 A. have the disconnected leads taped to prevent ... D. have one lead grounded to discharge static electricity for the prevention of damage to electronic components

Last Answer : Answer: C

Description : __________ is used for measuring the static pressure exerted on the wall by a fluid flowing parallel to the wall in a pipeline. (A) Venturimeter (B) Pressure gauge (C) Pitot tube (D) Orificemeter

Last Answer : (C) Pitot tube

Description : Liquid delivery by centrifugal pump starts, only when the head developed by it is equal to the __________ head. (A) Manometric (B) Total (C) Static (D) Friction

Last Answer : (A) Manometric

Description : The simple Pitot tube measures the __________ pressure. (A) static (B) Dynamic (C) Total (D) None of these

Last Answer : (C) Total

Description : The __________ is measured by a piezometric opening. (A) Dynamic pressure (B) Static pressure (C) Total pressure (D) Point velocity

Last Answer : (C) Total pressure

Description : A piezometer opening measures the __________ fluid pressure. (A) Static (B) Undisturbed (C) Total (D) Dynamic

Last Answer : (B) Undisturbed

Description : __________ do not take their decisions on measurements or estimates of the current traffic and topology. a. Static algorithms b. Adaptive algorithms c. Non - adaptive algorithms d. Recursive algorithms

Last Answer : c. Non - adaptive algorithms

Description : The pitot static tube does not measure the __________ pressure. (A) Static (B) Total (C) Difference in static & dynamic (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)