Which of the following statements identifies the difference between the primary windings and the secondary windings of a 2:1 stepdown transformer? A. The secondary windings have twice as much resistance as the primary windings. B. The secondary windings give off twice as much heat as the primary windings. C. The secondary windings require half as much current as the primary windings. D. The secondary windings have half as many turns as the primary windings.

Which of the following statements identifies the difference between the primary windings and the secondary windings of a 2:1 stepdown transformer? A. The secondary windings have twice as much resistance as the primary windings. B. The secondary windings give off twice as much heat as the primary windings. C. The secondary windings require half as much current as the primary windings. D. The secondary windings have half as many turns as the primary windings.
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Answer: D
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Related questions

Which of the following statements is true concerning stepdown transformer operation? A. The inductance on the primary side is the same as the inductance on the secondary side. B. The voltage to the primary side is the same as the voltage from the secondary side. C. The current to the primary side is the same as the current from the secondary side. D. The voltage to the primary side is greater than the voltage from the secondary side.

Description : Which of the following statements is true concerning stepdown transformer operation? A. The inductance on the primary side is the same as the inductance on the secondary side. B. The voltage to the primary ... . D. The voltage to the primary side is greater than the voltage from the secondary side.

Last Answer : Answer: D

Relative to the secondary winding of a step-up transformer, the primary winding will have _____________. A. more turns B. fewer turns C. half as many turns D. twice as many turns

Description : Relative to the secondary winding of a step-up transformer, the primary winding will have _____________. A. more turns B. fewer turns C. half as many turns D. twice as many turns

Last Answer : Answer: B

When a low input voltage is imparted to a device which then delivers a high output voltage, the device is known as a _____________. A. primary transformer B. secondary transformer C. stepdown transformer D. stepup transformer

Description : When a low input voltage is imparted to a device which then delivers a high output voltage, the device is known as a _____________. A. primary transformer B. secondary transformer C. stepdown transformer D. stepup transformer

Last Answer : Answer: D

Increasing the load to the secondary windings of a transformer will cause a/an ____________. A. decrease in the primary voltage B. increase in the primary voltage C. decrease in the primary current D. increase in the primary current

Description : Increasing the load to the secondary windings of a transformer will cause a/an ____________. A. decrease in the primary voltage B. increase in the primary voltage C. decrease in the primary current D. increase in the primary current

Last Answer : Answer: D

Which of the following statements is true concerning a stepdown transformer in an operating AC power circuit? A. Voltage and current will both be increased. B. Voltage and current will both be decreased C. Voltage decreases as current increases. D. Voltage increases as current decreases.

Description : Which of the following statements is true concerning a stepdown transformer in an operating AC power circuit? A. Voltage and current will both be increased. B. Voltage and current will both be decreased C. Voltage decreases as current increases. D. Voltage increases as current decreases.

Last Answer : Answer: C

On AC vessels, which of the following statements represents the most difficult problem involved in obtaining a DC potential suitable for use by computer components? A. A stepdown transformer is always required. B. Vessel vibrations affect the voltage source. C. The voltage must be rectified and made ripple free. D. Rectifiers cannot operate with voltage regulators.

Description : On AC vessels, which of the following statements represents the most difficult problem involved in obtaining a DC potential suitable for use by computer components? A. A stepdown transformer is ... voltage must be rectified and made ripple free. D. Rectifiers cannot operate with voltage regulators.

Last Answer : Answer: C

The function of a stepdown potential transformer is to reduce the load _____________. A. voltage and current B. voltage and increase line current C. current and increase line voltage D. power

Description : The function of a stepdown potential transformer is to reduce the load _____________. A. voltage and current B. voltage and increase line current C. current and increase line voltage D. power

Last Answer : Answer: B

21.The ordinary two winding transformer's primary and secondary windings always have A. different no of turns B. same size of copper wire C. a common magnetic circuit D. separate magnetic circuits

Description : 21.The ordinary two winding transformer's primary and secondary windings always have A. different no of turns B. same size of copper wire C. a common magnetic circuit D. separate magnetic circuits

Last Answer : C. A common magnetic circuit

In potential transformers, the secondary turns are increased slightly and the primary and secondary windings...

Description : In potential transformers, the secondary turns are increased slightly and the primary and secondary windings are wound as closely as possible to compensate for  (a) Phase angle and ratio error, ... loss and hysteresis loss, respectively  (d) The hysteresis loss and eddy current loss, respectively

Last Answer : In potential transformers, the secondary turns are increased slightly and the primary and secondary windings are wound as closely as possible to compensate for Ratio and phase angle error, respectively 

A 1:5 step-up transformer has 120V across the primary and 600 ohms resistance across the secondary. Assuming 100% efficiency, the primary current equals (A) 0.2 Amp. (B) 5 Amps. (C) 10 Amps. (D) 20 Amps.

Description : A 1:5 step-up transformer has 120V across the primary and 600 ohms resistance across the secondary. Assuming 100% efficiency, the primary current equals (A) 0.2 Amp. (B) 5 Amps. (C) 10 Amps. (D) 20 Amps.

Last Answer : I1= V1 /R1 = 120/600 = 0.2 (η = 100%, losses are zero ∴V1 = VR = I1R1)

29. In transformer terminology, the ratio 20:1 indicates that A. there are 20 turns on primary one turn on secondary B. secondary voltage is 1/20th of the primary C. primary current is 20 times greater than the secondary current D. for every 0 turns on primary, there is one turn on secondary

Description : 29.In transformer terminology, the ratio 20:1 indicates that A. there are 20 turns on primary one turn on secondary B. secondary voltage is 1/20th of the primary C. primary current is 20 times greater than the secondary current D. for every 0 turns on primary, there is one turn on secondary

Last Answer : A. there are 20 turns on primary one turn on secondary

The doorbell on your house requires a 12 volt alternating current. A transformer having a primary winding of 1,600 turns is to be used to step down your house's 110-volt alternating current. How many turns are there on the secondary winding?

Description : The doorbell on your house requires a 12 volt alternating current. A transformer having a primary winding of 1,600 turns is to be used to step down your house's 110-volt alternating current. How many turns are there on the secondary winding?

Last Answer : ANSWER: 175 TURNS 

The leads to the primary and the high-voltage secondary windings of a power transformer usually are of what color?

Description : The leads to the primary and the high-voltage secondary windings of a power transformer usually are of what color?

Last Answer : Primary leads-black; secondary leads red.

Which of the listed transformer uses a single winding to produce voltage transformation? A. Stepup transformers B. Stepdown transformers C. Autotransformers D. Isolation transformers

Description : Which of the listed transformer uses a single winding to produce voltage transformation? A. Stepup transformers B. Stepdown transformers C. Autotransformers D. Isolation transformers

Last Answer : Answer: C

What is the maximum current allowed to be drawn from the secondary of a 2 KVA step-down transformer with a turns ratio of four to one if connected across a 440 volt line? A. 1.1 amps B. 4.5 amps C. 18.1 amps D. 22.7 amps

Description : What is the maximum current allowed to be drawn from the secondary of a 2 KVA step-down transformer with a turns ratio of four to one if connected across a 440 volt line? A. 1.1 amps B. 4.5 amps C. 18.1 amps D. 22.7 amps

Last Answer : Answer: C

What is the maximum allowable primary current of a 2 KVA step-down transformer with a four to one turns ratio if connected across a 440 volt line? A. 1.1 amps B. 4.5 amps C. 18.1 amps D. 27.7 amps

Description : What is the maximum allowable primary current of a 2 KVA step-down transformer with a four to one turns ratio if connected across a 440 volt line? A. 1.1 amps B. 4.5 amps C. 18.1 amps D. 27.7 amps

Last Answer : Answer: B

If we give 2334 A, 540V on Primary side of 1.125 MVA step up transformer, then what will be the Secondary Current, If Secondary Voltage=11 KV?

Description : If we give 2334 A, 540V on Primary side of 1.125 MVA step up transformer, then what will be the Secondary Current, If Secondary Voltage=11 KV?

Last Answer : A. As we know the Voltage & current relation for transformer-V1/V2 = I2/I1 We Know, VI= 540 V; V2=11KV or 11000 V; I1= 2334 Amps. By putting these value on Relation540/11000= I2/2334 So,I2 = 114.5 Amps

If we give 2334 A, 540V on Primary side of 1.125 MVA step up transformer, then what will be the Secondary Current, If Secondary Voltage=11 KV?

Description : If we give 2334 A, 540V on Primary side of 1.125 MVA step up transformer, then what will be the Secondary Current, If Secondary Voltage=11 KV?

Last Answer :  As we know the Voltage & current relation for transformer-V1/V2 = I2/I1 We Know, VI= 540 V; V2=11KV or 11000 V; I1= 2334 Amps. By putting these value on Relation540/11000= I2/2334 So,I2 = 114.5 Amps

The electrical diagram shown in the illustration is used to depict a/an ____________. EL-0015 A. resistance circuit B. inductive circuit C. stepdown circuit D. capacitive circuit

Description : The electrical diagram shown in the illustration is used to depict a/an ____________. EL-0015 A. resistance circuit B. inductive circuit C. stepdown circuit D. capacitive circuit

Last Answer : Answer: D

A transformer steps down 220V to 40 volts. If the secondary turns are 40 then primary turns will be: a. 20 b. 40 c. 120 d. 220

Description : A transformer steps down 220V to 40 volts. If the secondary turns are 40 then primary turns will be: a. 20 b. 40 c. 120 d. 220

Last Answer : d. 220V

52 A transformer has 1000 primary turns, connected to 250V ac supply. To get 400V secondary voltage the no of secondary turns should be A. 1600 B. 250 C. 400 D. 1250

Description : 52 A transformer has 1000 primary turns, connected to 250V ac supply. To get 400V secondary voltage the no of secondary turns should be A. 1600 B. 250 C. 400 D. 1250

Last Answer : A. 1600

When the turns ratio of a transformer is 20 and the primary ac voltage is 12 V, the secondary voltage is?

Description : When the turns ratio of a transformer is 20 and the primary ac voltage is 12 V, the secondary voltage is? A.12 V B.120 V C.240 V D.2,400 V

Last Answer : When the turns ratio of a transformer is 20 and the primary ac voltage is 12 V, the secondary voltage is? A.12 V B.120 V C.240 V D.2,400 V

A certain transformer has 400 turns in the primary winding and 2,000 turns in the secondary

Description : A certain transformer has 400 turns in the primary winding and 2,000 turns in the secondary winding. The turns ratio is? A.0.2 B.0.4 C.5 D.25

Last Answer : A certain transformer has 400 turns in the primary winding and 2,000 turns in the secondary winding. The turns ratio is? A.0.2 B.0.4 C.5 D.25

If a transformer has 50 turns in the primary winding and 10 turns in the secondary winding,

Description : If a transformer has 50 turns in the primary winding and 10 turns in the secondary winding, what is the reflective resistance if the secondary load resistance is 250 ohms? A.250 ohms B.25 ohms C.6,250 ohms D.62,500 ohms

Last Answer : 6,250 ohms

The turns ratio of a transformer having 200 primary turns and 1,200 secondary turns is?

Description : The turns ratio of a transformer having 200 primary turns and 1,200 secondary turns is? A.6 B.24 C.1.66 D.66

Last Answer : The turns ratio of a transformer having 200 primary turns and 1,200 secondary turns is? A.6 B.24 C.1.66 D.66

If the secondary turns of a transformer are doubled and at the same time primary voltage is

Description : If the secondary turns of a transformer are doubled and at the same time primary voltage is reduced to half then the secondary voltage will

Last Answer : If the secondary turns of a transformer are doubled and at the same time primary voltage is reduced to half then the secondary voltage will not change

A certain transformer has 200 turns in the primary winding, 50 turns in the secondary winding and 120 volts

Description : A certain transformer has 200 turns in the primary winding, 50 turns in the secondary winding and 120 volts applied to the primary. What is the voltage across the secondary?  (A) 30 Volts (B) 480 Volts (C) 120 Volts (D) 60 Volts

Last Answer : A certain transformer has 200 turns in the primary winding, 50 turns in the secondary winding and 120 volts applied to the primary. What is the voltage across the secondary?  (A) 30 Volts (B) 480 Volts (C) 120 Volts (D) 60 Volts

A load with an impedance of 440 ohms is connected across the secondary of the transformer illustrated. If the input voltage is 110 VAC and the step-up ratio is 10 to 1, what will be the primary current? EL-0055 A. 2.5 amps B. 25 amps C. 250 amps D. current cannot be determined with information given

Description : A load with an impedance of 440 ohms is connected across the secondary of the transformer illustrated. If the input voltage is 110 VAC and the step-up ratio is 10 to 1, what will be the primary current? EL-0055 A. 2.5 amps B. 25 amps C. 250 amps D. current cannot be determined with information given

Last Answer : Answer: B

A load is connected to the secondary of the transformer illustrated and the current through the load is 10 amps. If the step-up ratio is 10 to 1 and the input voltage is 110 VAC, what will be the current flow through the primary? EL-0055 A. 1 amp B. 10 amps C. 100 amps D. 1000 amps

Description : A load is connected to the secondary of the transformer illustrated and the current through the load is 10 amps. If the step-up ratio is 10 to 1 and the input voltage is 110 VAC, what will be the current flow through the primary? EL-0055 A. 1 amp B. 10 amps C. 100 amps D. 1000 amps

Last Answer : Answer: C

What current flows in the transformer primary when its secondary is open?

Description : What current flows in the transformer primary when its secondary is open?

Last Answer : A. When the secondary is open, there is no current in the secondary of the transformer. The primary takes a small current I0) from the source called no-load current which has a magnetizing ... ) producing the magnetic flux and a working component (I0 cosθ0) supplying real power for iron losses.

Which of the following statements comparing transistors and vacuum tubes is correct? A. Both transistors and vacuum tubes have a cathode that must be heated to give off electrons. B. A vacuum tube must have a heated cathode, where transistors do not. C. Neither transistors nor vacuum tubes require heat for electrons to flow. D. The anode of both transistors and vacuum tubes must be heated to give off electrons.

Description : Which of the following statements comparing transistors and vacuum tubes is correct? A. Both transistors and vacuum tubes have a cathode that must be heated to give off electrons. B. A vacuum tube must ... flow. D. The anode of both transistors and vacuum tubes must be heated to give off electrons.

Last Answer : Answer: B

In a three phase transformer, if the primary side is connected in star and secondary side is connected in delta, what is the angle difference between phase voltage in the two cases. (A) delta side lags by -30°. (B) star side lags by -30°. (C) delta side leads by 30°. (D) star side leads by -30°.

Description : In a three phase transformer, if the primary side is connected in star and secondary side is connected in delta, what is the angle difference between phase voltage in the two cases. (A) delta side lags by -30°. (B) star side lags by -30°. (C) delta side leads by 30°. (D) star side leads by -30°.

Last Answer : Ans: C This is vector group and has +30° displacement. Therefore, delta side leads by +30°.

Damp armature windings in a D.C. motor may lead to ____________. A. reduced voltage B. reduced current C. increased resistance D. overheating

Description : Damp armature windings in a D.C. motor may lead to ____________. A. reduced voltage B. reduced current C. increased resistance D. overheating

Last Answer : Answer: D

Moisture absorbed in the windings or condensed on the surface of electrical machinery insulation ________. A. is good for long term preserving since most insulation is organic and contains some amount B. lowers the insulation value and is a common cause of fault grounds in idle machines C. will enhance insulation resistance only if it is fresh water and contains no salt D. reduces the amount of current supplied or drawn by the machine so horsepower is limited

Description : Moisture absorbed in the windings or condensed on the surface of electrical machinery insulation ________. A. is good for long term preserving since most insulation is organic and contains some amount B. ... D. reduces the amount of current supplied or drawn by the machine so horsepower is limited

Last Answer : Answer: B

You are testing the insulation in an AC generator with a megohmeter. The resistance value of a dry, clean winding will ____________. A. continue to rise as the test potential is maintained, becoming fairly steady as the leakage current stabilizes B. remain constant as the temperature of the windings increases C. continue to drop as the potential is maintained, becoming fairly steady after 5 to 7 minutes D. stabilize after approximately 2 to 4 minutes of fluctuation

Description : You are testing the insulation in an AC generator with a megohmeter. The resistance value of a dry, clean winding will ____________. A. continue to rise as the test potential is maintained, ... fairly steady after 5 to 7 minutes D. stabilize after approximately 2 to 4 minutes of fluctuation

Last Answer : Answer: A

When a megohmmeter is used to test insulation, the gradual rise of the pointer reading as a result of continued cranking, is caused by _____________. A. good conductor resistance B. the leakage of current along the surface of dirty insulation C. the inductive reactance of the windings D. the dielectric-absorption effect of the insulation

Description : When a megohmmeter is used to test insulation, the gradual rise of the pointer reading as a result of continued cranking, is caused by _____________. A. good conductor resistance B. the ... insulation C. the inductive reactance of the windings D. the dielectric-absorption effect of the insulation

Last Answer : Answer: D

Which of the following statements describes what will happen when both the polarity of the field poles, and the direction of current to the brushes of a DC motor are reversed? A. The motor will not start. B. The direction of rotation of the armature will be reversed. C. The direction of rotation of the armature will remain the same. D. The field pole windings will become overheated.

Description : Which of the following statements describes what will happen when both the polarity of the field poles, and the direction of current to the brushes of a DC motor are reversed? A. The motor will ... of rotation of the armature will remain the same. D. The field pole windings will become overheated.

Last Answer : Answer: C

The purpose of the automatic bus transfer shown in the illustration is to ___________. EL-0014 A. stepdown voltage to the lighting distribution panel B. provide emergency power to the lighting distribution panel C. energize the emergency switchboard from the main switchboard D. provide overcurrent protection to the lighting distribution panel

Description : The purpose of the automatic bus transfer shown in the illustration is to ___________. EL-0014 A. stepdown voltage to the lighting distribution panel B. provide emergency power to ... emergency switchboard from the main switchboard D. provide overcurrent protection to the lighting distribution panel

Last Answer : Answer: B

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 bearings C. strictly converted to heat generated by current flow through the windings D. transmitted directly through the rotor shaft to perform useful work

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

Last Answer : Answer: A

A wire is being used as a replacement having twice the length and one-half the cross-sectional area of the original wire. The resistance of this new wire, when compared to that of the original wire, is _____________. A. four times as great B. twice as much C. the same as the original resistance D. one-half of the original resistance

Description : A wire is being used as a replacement having twice the length and one-half the cross-sectional area of the original wire. The resistance of this new wire, when compared to that of the original wire, ... B. twice as much C. the same as the original resistance D. one-half of the original resistance

Last Answer : Answer: A

In a transformer, with closed magnetic coupling between primary and secondary __ will improve: a) Efficiency b) All day efficiency c) Regulation d) None of the above

Description : In a transformer, with closed magnetic coupling between primary and secondary __ will improve: a) Efficiency b) All day efficiency c) Regulation d) None of the above

Last Answer : Ans: C

When a transformer is used to step down voltage, the low voltage winding is _____________. A. part of the core B. the primary coil C. not insulated D. the secondary coil

Description : When a transformer is used to step down voltage, the low voltage winding is _____________. A. part of the core B. the primary coil C. not insulated D. the secondary coil

Last Answer : Answer: D

If a transformer is connected to a DC source, the transformer will overload at the ____________. A. contacts B. primary coil C. secondary coil D. core

Description : If a transformer is connected to a DC source, the transformer will overload at the ____________. A. contacts B. primary coil C. secondary coil D. core

Last Answer : Answer: B

In a Tap changing transformer on which side is the tap connected, primary side or secondary side?

Description : In a Tap changing transformer on which side is the tap connected, primary side or secondary side?

Last Answer : A. Tapings are always connected to high voltage winding side, because of low current. If we connect tapings to low voltage side, sparks will produce while tap changing operation due to high current.

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.

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.

A CT has 2 – secondary windings. If we use only one secondary winding can we keep the unused secondary winding short circuited?

Description : A CT has 2 – secondary windings. If we use only one secondary winding can we keep the unused secondary winding short circuited?

Last Answer : No. If it is short-circuited then the ratio will not get correctly. The turns of primary winding will be shared between 2 secondary windings. So the unused secondary winding should kept open. 

57 In a transformer the resistance between its primary and secondary is A. Zero B. 1Ω C. 1000 Ω D. Infinite

Description : 57 In a transformer the resistance between its primary and secondary is A. Zero B. 1Ω C. 1000 Ω D. Infinite

Last Answer : D. Infinite

50 The equivalent resistance of the primary of the transformer having K = 5, R1 = 0.1 ohm when referred to secondary becomes .....ohm A. 0.5 B. 0.02 C. 0.004 D. 2.5

Description : 50 The equivalent resistance of the primary of the transformer having K = 5, R1 = 0.1 ohm when referred to secondary becomes .....ohm A. 0.5 B. 0.02 C. 0.004 D. 2.5

Last Answer : A. 0.5