Autotransformer

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Autotransformer

asked Jul 6, 2019 by anonymous

1 Answer

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Last Answer : 由BillC - 自己的作品，CC BY-SA 3.0，链接 Autotransformer is a special case in which one coil becomes part of another coil. Autotransformers are also often used for motor starting. Autotransformer ... low loss, low cost and widely used. source: https://zh.wikipedia.org/zh-hans/%E5%8F%98%E5%8E%8B%E5%99%A8

The electrical schematic illustrated in figure A, depicts a/an _____________. EL-0059 A. autotransformer B. Delta Wye transformer C. primary EMF generator D. potential transformer

Description : The electrical schematic illustrated in figure A, depicts a/an _____________. EL-0059 A. autotransformer B. Delta Wye transformer C. primary EMF generator D. potential transformer

Last Answer : Answer: D

The electrical schematic shown in the illustration represents a/an ____________. EL-0017 A. across-the-line starter B. primary-resistor starter C. autotransformer starter D. part-winding starter

Description : The electrical schematic shown in the illustration represents a/an ____________. EL-0017 A. across-the-line starter B. primary-resistor starter C. autotransformer starter D. part-winding starter

Last Answer : Answer: A

The diagram shown in the illustration represents a/an _____________. EL-0082 A. stepup transformer B. magnetic amplifier C. autotransformer D. Scott-connected transformer

Description : The diagram shown in the illustration represents a/an _____________. EL-0082 A. stepup transformer B. magnetic amplifier C. autotransformer D. Scott-connected transformer

Last Answer : Answer: A

An autotransformer is equipped with a 50% tap, a 65% tap, and an 80% tap. Which of the following statements is true concerning a load connected to the 50% tap? A. The load is receiving minimum voltage and minimum current. B. The load is receiving minimum voltage and maximum current. C. The load is receiving maximum voltage and minimum current. D. The load is receiving maximum voltage and maximum current.

Description : An autotransformer is equipped with a 50% tap, a 65% tap, and an 80% tap. Which of the following statements is true concerning a load connected to the 50% tap? A. The load is ... is receiving maximum voltage and minimum current. D. The load is receiving maximum voltage and maximum current.

Last Answer : Answer: B

Which of the listed types of motor controllers and starters is illustrated? EL-0080 A. Across-the-line B. Primary-resistor C. Autotransformer D. Part-winding

Description : Which of the listed types of motor controllers and starters is illustrated? EL-0080 A. Across-the-line B. Primary-resistor C. Autotransformer D. Part-winding

Last Answer : Answer: C

The voltage at the reference electrode of the circuit shown in the illustration is applied to the input of a/an ______________. EL-0090 A. class A detector whose output drives an autotransformer B. operational amplifier whose output controls a step-up voltage reactor C. amplitude modulator whose output drives an 2-stage isolation transformer D. magnetic amplifier whose output controls a saturable reactor

Description : The voltage at the reference electrode of the circuit shown in the illustration is applied to the input of a/an ______________. EL-0090 A. class A detector whose output drives an ... drives an 2-stage isolation transformer D. magnetic amplifier whose output controls a saturable reactor

Last Answer : Answer: D

Most three-phase induction motors of five horsepower or less, are started by _____________. A. autotransformer starters B. resistor starters C. across-the-line starters D. reactor starters

Description : Most three-phase induction motors of five horsepower or less, are started by _____________. A. autotransformer starters B. resistor starters C. across-the-line starters D. reactor starters

Last Answer : Answer: C

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 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

Last Answer : Answer: B

Autotransformer starters or compensators are sometimes used with polyphase induction motors to _____________. A. reduce the voltage applied to the motor during the starting period B. increase the voltage for 'across-the-line starting' C. provide a backup means of voltage regulation for emergency starting D. allow the voltage to be either stepped up or down, depending on the application, to ensure full torque

Description : Autotransformer starters or compensators are sometimes used with polyphase induction motors to _____________. A. reduce the voltage applied to the motor during the starting period B. increase the voltage for ' ... to be either stepped up or down, depending on the application, to ensure full torque

Last Answer : Answer: A

In general, polyphase induction motors can be started on full line voltage by means of ______________. A. compensator starters B. autotransformer starters C. across-the-line starters D. primary-resistor starters

Description : In general, polyphase induction motors can be started on full line voltage by means of ______________. A. compensator starters B. autotransformer starters C. across-the-line starters D. primary-resistor starters

Last Answer : Answer: C

Low horsepower, polyphase, induction motors can be started with full voltage by means of _____________. A. compensator starters B. autotransformer starters C. across-the-line starters D. primary-resistor starters

Description : Low horsepower, polyphase, induction motors can be started with full voltage by means of _____________. A. compensator starters B. autotransformer starters C. across-the-line starters D. primary-resistor starters

Last Answer : Answer: C

As shown in the illustration, which of the listed types of motor controllers and starters is indicated? EL-0012 A. Across-the-line B. Capacitor C. Autotransformer D. Part-winding

Description : As shown in the illustration, which of the listed types of motor controllers and starters is indicated? EL-0012 A. Across-the-line B. Capacitor C. Autotransformer D. Part-winding

Last Answer : Answer: C

List the merits of an autotransformer.

Description : List the merits of an autotransformer.

Last Answer : Require less conductor material low cost low size high VA rating high efficiency Better voltage regulation small amount of no load current

Compare autotransformer with two winding transformer.

Description : Compare autotransformer with two winding transformer.

Last Answer : Two winding transformer Auto transformer 1.It has two separate windings : a) primary, b)secondary. 1. An auto transformer has single winding which acts both as primary and secondary ... varied. 3. They find application as boosters in AC feeders to increase the voltage levels.

State any two applications of single phase autotransformer.

Description : State any two applications of single phase autotransformer.

Last Answer : Applications of single phase auto transformers: 1) Give small boost to distribution cable to correct the voltage drop. 2) As auto transformer starter for induction motors. 3) As furnace supply ... . 5) In control equipment for single phase locomotives. 6) As dimmer in lighting circuits.

State with neat sketch the construction of three phase autotransformer.

Description : State with neat sketch the construction of three phase autotransformer.

Last Answer : Operation: Working principle is based on self-induction. When three-phase ac supply is given to star connected three windings, flux is produced and gets linked with each phase winding. The emf ... . Depending upon the position of variable terminal, we get variable AC voltage at the output.

Draw the power and control circuit for motors using autotransformer type starter.

Description : Draw the power and control circuit for motors using autotransformer type starter.

Last Answer : Draw the power and control circuit for motors using autotransformer type starter.

3kW load is supplied by an autotransformer with 0.7 transformation ratio. Conductively transferred power

Description : 3kW load is supplied by an autotransformer with 0.7 transformation ratio. Conductively transferred power from primary to secondary is (A) 2.1 kW (B) 0.9 kW (C) 4.29 kW (D) 3 kW

Last Answer : 3kW load is supplied by an autotransformer with 0.7 transformation ratio. Conductively transferred power from primary to secondary is 2.1 kW

AC power plugs and sockets

Description : AC power plugs and sockets