In an actual transformer the iron loss remains practically constant from no load to full load because?
Last Answer : In an actual transformer the iron loss remains practically constant from no load to full load because core flux remains practically constant.
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1 answer
asked
Mar 19, 2018
by
anonymous

Last Answer : Iron loss of a transformer can be measured by low power factor wattmeter.
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104 views
1 answer
asked
Mar 19, 2018
by
anonymous

At full -load of a transformer, the iron loss and copper loss are 3000 W and 4000 W respectively. Then total loss at maximum efficiency is : (A) 7000 W (B) 6000 W (C) 8000 W (D) 4000 W
Last Answer : At full -load of a transformer, the iron loss and copper loss are 3000 W and 4000 W respectively. Then total loss at maximum efficiency is : 6000 W
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303 views
1 answer
asked
Apr 30, 2018
by
anonymous
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The effective resistance of an iron-cored choke working on ordinary supply frequency is more than its true resistance because of?
Last Answer : The effective resistance of an iron-cored choke working on ordinary supply frequency is more than its true resistance because of iron loss in core.
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169 views
1 answer
asked
Mar 25, 2018
by
anonymous
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When secondary of a current transformer is open-circuited its iron core will be?
Last Answer : When secondary of a current transformer is open-circuited its iron core will be hot because of heavy iron losses taking place in it due to high flux density.
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165 views
1 answer
asked
Mar 19, 2018
by
anonymous

In a step-down transformer, there is a change of 15 A in the load current. This results in change of supply current of?
Last Answer : In a step-down transformer, there is a change of 15 A in the load current. This results in change of supply current of less than 15A.
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156 views
1 answer
asked
Mar 19, 2018
by
anonymous

A ferrite core has less eddy current loss than an iron core because?
Last Answer : A ferrite core has less eddy current loss than an iron core because ferrites have high hysteresis.
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382 views
1 answer
asked
Mar 25, 2018
by
anonymous

Last Answer : If the synchronous motor, properly synchronised to the supply is running on no load and is having negligible loss then the stator current will be zero.
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116 views
1 answer
asked
Mar 20, 2018
by
anonymous

The SCR would be turned OFF by voltage reversal of applied anode-cathode ac supply frequency of A) 10 kHz B) 10 Hz C) 5 kHz D) 5 Hz
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186 views
0 answers
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Jun 18, 2018
by
anonymous

The time period of third harmonic of power supply frequency, in milliseconds, is (A) 20 (B) 3.33 (C) 6.66 (D) 60
Last Answer : The time period of third harmonic of power supply frequency, in milliseconds, is 6.66
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540 views
1 answer
asked
Apr 28, 2018
by
anonymous

An AC supply of 230 V is applied to a half-wave rectifier circuit through a transformer having primary to secondary turn’s ratio 12:1. The peak inverse voltage is A) 8.62 V B) 12 V C) 19.17 V D) 27.11 V
Last Answer : An AC supply of 230 V is applied to a half-wave rectifier circuit through a transformer having primary to secondary turn’s ratio 12:1. The peak inverse voltage is A) 8.62 V B) 12 V C) 19.17 V D) 27.11 V
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259 views
1 answer
asked
Jun 18, 2018
by
anonymous

What will happen if the primary of a transformer is connected to D.C. supply? (A) Transformer will operate with low efficiency (B) Transformer will operate with high efficiency (C) No effect (D) Transformer may start to smoke and burn
Last Answer : What will happen if the primary of a transformer is connected to D.C. supply? (A) Transformer will operate with low efficiency (B) Transformer will operate with high efficiency (C) No effect (D) Transformer may start to smoke and burn
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541 views
1 answer
asked
May 8, 2018
by
anonymous

Why does a transformer only work with an AC supply?
Last Answer : The transformer work depends on the induction as main principle ,for that AC is the right means
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150 views
3 answers
asked
Mar 14, 2018
by
anonymous
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The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as?
Last Answer : The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as pull-in torque.
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302 views
1 answer
asked
Mar 20, 2018
by
anonymous

The maximum torque which a synchronous motor will develop at rest for any angular position of the rotor, at rated stator supply voltage and frequency, is known as?
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106 views
0 answers
asked
Mar 20, 2018
by
anonymous

A 40 kVA transformer has a core loss of 400 W and a full load copper loss of 800 W. The proportion of full load at maximum efficiency is
Last Answer : A 40 kVA transformer has a core loss of 400 W and a full load copper loss of 800 W. The proportion of full load at maximum efficiency is 0.707
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774 views
1 answer
asked
May 8, 2018
by
anonymous

What would happen if a power transformer designed for operation on 50 Hz (frequency) were connected to a 500 Hz (frequency) source of the same voltage: (A) Eddy Current and Hysteresis losses will be ... Current will be too much high (C) Transformer may start to smoke and burn (D) No effect
Last Answer : What would happen if a power transformer designed for operation on 50 Hz (frequency) were connected to a 500 Hz (frequency) source of the same voltage: (A) Eddy Current and Hysteresis losses will be ... will be too much high (C) Transformer may start to smoke and burn (D) No effect
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795 views
1 answer
asked
May 8, 2018
by
anonymous

Stability of a transmission line can be increased by
Last Answer : Stability of a transmission line can be increased by Shunt capacitor, Series capacitor
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363 views
1 answer
asked
May 8, 2018
by
anonymous

Last Answer : As the load is increased the speed of D.C. shunt motor will reduce slightly.
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142 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : The increased load during summer months is due to increased use of fans and air conditioners.
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59 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : The steady state stability of the power system can be increased by connecting lines in parallel.
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118 views
1 answer
asked
Mar 20, 2018
by
anonymous

If the load of the normally excited synchronous motor is increased the power factor will?
Last Answer : If the load of the normally excited synchronous motor is increased the power factor will become lagging.
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150 views
1 answer
asked
Mar 18, 2018
by
anonymous

For given applied voltage, with the increase in frequency of the applied voltage?
Last Answer : For given applied voltage, with the increase in frequency of the applied voltage eddy current loss will remain unchanged.
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238 views
1 answer
asked
Mar 19, 2018
by
anonymous

Select insulating materials for following parts : (i) Insulation between heating element and base plate of electric iron. (ii) Insulation used over copper or aluminium conductor used for making coils. (iii) Transformer bushings. (iv) Insulation between transmission line and pole.
Last Answer : Parts Insulating Materials Insulation between heating element and base plate of electric iron. Mica Insulation used over copper or aluminium conductor used for making coils. ... Transformer bushings Porcelain Insulation between transmission line and pole. Porcelain
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199 views
1 answer
asked
May 7, 2020
by
anonymous

[53] The iron loss of the transformer is negligible during short circuit test because A. The entire input is just sufficient to meet Cu losses only B. Flux produced is a small fraction of the normal flux C. Iron core becomes fully saturated D. Supply frequency is held constant
Last Answer : B. Flux produced is a small fraction of the normal flux
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54 views
1 answer

Last Answer : A transformer cannot raise or lower the voltage of a D.C. supply because Faraday's laws of electromagnetic induction are not valid since the rate of change of flux is zero.
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344 views
1 answer
asked
Mar 19, 2018
by
anonymous
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Last Answer : The core used in high frequency transformer is usually air core .
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214 views
1 answer
asked
Mar 19, 2018
by
anonymous

Last Answer : When a given transformer is run at its rated voltage but reduced frequency, its core flux density is increased.
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110 views
1 answer
asked
Mar 19, 2018
by
anonymous

The eddy current loss in a dc generator is 400 W at 40 Hz frequency of reversal and constant flux density. When frequency is increased to 50 Hz., eddy current loss is : (A) 256 W (B) 320 W (C) 500 W (D) 625 W
Last Answer : The eddy current loss in a dc generator is 400 W at 40 Hz frequency of reversal and constant flux density. When frequency is increased to 50 Hz., eddy current loss is : 625 W
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103 views
1 answer
asked
Apr 30, 2018
by
anonymous

Last Answer : The full-load copper loss of a trans¬former is 1600 W. At half-load, the copper loss will be 400 W.
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149 views
1 answer
asked
Mar 19, 2018
by
anonymous

Last Answer : The purpose of providing an iron core in a transformer is to decrease the reluctance of the magnetic path.
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203 views
1 answer
asked
Mar 19, 2018
by
anonymous

Last Answer : The purpose of providing iron core in a step-up transformer is to decrease the magnitude of magnetizing current.
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546 views
1 answer
asked
Mar 19, 2018
by
anonymous

What happens to the voltage in the secondary when the frequency of the supply in the primary is decreased? A) It increases B) It decreases C) It remains the same D) Cannot say unless the actual percentage increase in the frequency is known
Last Answer : What happens to the voltage in the secondary when the frequency of the supply in the primary is decreased? A) It increases B) It decreases C) It remains the same D) Cannot say unless the actual percentage increase in the frequency is known
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119 views
1 answer
asked
Apr 29, 2018
by
anonymous

Do you iron your clothes?
Last Answer : Lika hail no!
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1 view
1 answer
asked
Mar 5
by
anonymous

Which Foods are Good Sources of Iron?
Last Answer : Google, Google and Google some more. I did this for iron rich foods just 2 days ago and there is a plethora of great information. Also, do what your Dr. told you, but I do find that slow release iron supplements (like slow-fe) are far easier on your system.
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0 views
1 answer
asked
Feb 26
by
anonymous

How to Clean Wrought Iron
Last Answer : How to Clean Wrought Iron Items made from wrought iron can look beautiful, grand and elegant, but it only takes a few years for them to make your house looking like a haunted house more than an elegant ... of time. Chances are, you will just have to paint over the stains to cover them up completely.
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8 views
1 answer
asked
May 12, 2021
by
anonymous

How to Iron Jeans ?
Last Answer : How to Iron Jeans There's nothing like a pair of thoroughly wrinkled jeans to make one look unkempt and unhygienic. Learn how to iron your jeans properly, which will only make you look good, but it will ... can last for a week. You can also opt to iron your jeans once a week, after laundering.
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0 views
1 answer
asked
May 9, 2021
by
anonymous

How to Increase Iron in Your Diet ?
Last Answer : How to Increase Iron in Your Diet Iron is essential for the production of hemoglobin and myoglobin. These are important proteins needed in transporting oxygen throughout the body. Iron also improves ... iron sources in your diet to prevent acquiring diseases associated with low levels of iron.
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4 views
1 answer
asked
May 9, 2021
by
anonymous

How to Iron a Shirt ?
Last Answer : How to Iron a Shirt If you want to learn how to iron your own clothes, shirts are a good starting point. Shirts are typically the easiest to iron, and can be done perfectly in a short time. Here' ... fabric and beads should have a towel on top for an indirect contact, with the iron on a low setting.
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1 view
1 answer
asked
May 8, 2021
by
anonymous

How to Clean a Steam Iron ?
Last Answer : How to Clean a Steam Iron Ironing clothes with a steam iron is a relatively easy task, but if the appliance is not properly maintained, it will cause more harm than good. Steam irons become clogged ... ironing will not be a tedious task. Remember these steps and keep your steam iron in tiptop shape.
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9 views
1 answer
asked
May 8, 2021
by
anonymous

What to look for when choosing an iron?
Last Answer : What to look for when choosing an iron? Today, the purchase of an iron is not a big problem. This piece of household appliances is presented in a wide range of stores. Each manufacturer tries to ... its presence increases the cost of the iron by an average of 10%. Good luck with your choice!
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3 views
1 answer
asked
Mar 27, 2021
by
anonymous

Which is the best conductor: silver, carbon, or iron?
Last Answer : Silver is the best conductor. Carbon is the semiconductor. Iron have less conductance as compared to silver.
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162 views
1 answer
asked
Jul 1, 2019
by
anonymous

An unshielded moving iron voltmeter is used to measure the voltage in an AC circuit. The stray DC magnetic field having a component along the axis will be (1) unaffected (2) decreased (3) increased (4) either decreased or increased depending on the direction of the DC field
Last Answer : An unshielded moving iron voltmeter is used to measure the voltage in an AC circuit. The stray DC magnetic field having a component along the axis will be either decreased or increased depending on the direction of the DC field
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334 views
1 answer
asked
Apr 29, 2018
by
anonymous

The iron alloy, ALNICO is mainly used to make ________ A) Temporary magnets B) Permanent magnets C) Transmission lines D) None of these
Last Answer : The iron alloy, ALNICO is mainly used to make Permanent magnets
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88 views
1 answer
asked
Apr 29, 2018
by
anonymous

Eddy current damping cannot be used for moving iron instrument because
Last Answer : Eddy current damping cannot be used for moving iron instrument because the presence of a permanent magnet required for such purpose would affect the deflection and hence the reading of the instrument
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2.3k views
1 answer
asked
Apr 26, 2018
by
anonymous

In DC motor iron losses are occurred in?
Last Answer : In DC motor iron losses are occurred in the armature.
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138 views
1 answer
asked
Mar 26, 2018
by
anonymous

In AC. circuits, laminated iron is invariably used in order to?
Last Answer : In AC. circuits, laminated iron is invariably used in order to reduce eddy current loss.
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105 views
1 answer
asked
Mar 25, 2018
by
anonymous

Last Answer : A moving iron instrument can be used for both D.C. and A.C.
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191 views
1 answer
asked
Mar 21, 2018
by
anonymous

Last Answer : Iron losses in a D.C. machine are independent of variations in load.
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161 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : In a D.C. generator, the iron losses mainly take place in armature rotor.
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273 views
1 answer
asked
Mar 20, 2018
by
anonymous
