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why transformer don't work on DC supply?
asked
Dec 9, 2017
by
anonymous
why transformer don't work on DC supply?
transformer
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2
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answered
Jan 12, 2018
by
anonymous
DC can not produce changing magnetic flux that's why.
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answered
Jul 31, 2018
by
anonymous
A DC current does not produce a changing magnetic field which is capable of inducing current on the secondary windings of a transformer through mutual induction process.
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Related questions
asked
Mar 14, 2018
by
anonymous
Why does a transformer only work with an AC supply?
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
transformer
only
work
ac
supply
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109
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3
answers
asked
Apr 30, 2018
by
anonymous
The inrush current of a transformer at no load is maximum if the supply voltage is switched on
The inrush current of a transformer at no load is maximum if the supply voltage is switched on (1) at peak voltage value (2) at zero voltage value (3) at half voltage value (4) at 0.866 time voltage value
Last answer:
At 0.866 time voltage value
inrush
current
transformer
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80
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2
answers
asked
May 10, 2020
by
anonymous
Transformer on DC
Write about transformer on DC.
Last answer:
Transformer on DC : Transformer cannot work on DC. Transformer works on electromagnetic induction principle. Electromagnetic induction principle means when flux linking with coil changes and EMF induced in it ... winding insulation will burn. https://youtu.be/TVp_0fIfxqY
transformer
on
dc
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232
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1
answer
asked
May 8, 2018
by
anonymous
What will happen if the primary of a transformer is connected to D.C. supply?
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
transformer
dc
supply
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74
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1
answer
asked
Mar 14, 2018
by
anonymous
Why does the core of a transformer need to be laminated?
Why does the core of a transformer need to be laminated?
Last answer:
Transformer cores are laminated to reduce eddy current loss.
core
transformer
need
laminated
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73
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1
answer
asked
Dec 7, 2017
by
jihadio k jeeja
why transformer rating is measured in KVA?
Transformer generally rated in KVA
Last answer:
The power of transformer is apparent power because it has no power factor and it is the product of voltage and current.
transformer
-rating
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132
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2
answers
asked
Oct 5, 2017
by
anonymous
is efficiency of transformer is greater than electrical machine and why?
Last answer:
The efficiency of transformer is Greater than electrical Machine because there is no rotational losses in transformer and there is no air gap losses in transformer so losses is less in transformer compare to electrical machine so efficiency is higher in case of transformer.
transformer
efficiency
electrical
machines
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3
answers
asked
Sep 30, 2017
by
anonymous
why the Transformer core is laminated?
Last answer:
Transformer core is laminated to reduce Eddy current losses.
transformer
core
laminated
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answer
asked
Dec 12, 2018
by
Manikumar
Why dont we give the main supply and inverter supply to the Appliance
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118
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0
answers
asked
Jun 18, 2018
by
anonymous
An AC supply of 230 V is applied to a half-wave rectifier circuit through a transformer having primary to
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
ac
supply
half-wave
rectifier
circuit
transformer
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120
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1
answer
asked
Mar 19, 2018
by
anonymous
A transformer cannot raise or lower the voltage of a D.C. supply because?
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.
transformer
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1
answer
asked
Mar 19, 2018
by
anonymous
If the supply frequency to the transformer is increased, the iron loss will?
Last answer:
If the supply frequency to the transformer is increased, the iron loss will increase.
supply
frequency
transformer
increased
iron
loss
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102
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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?
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.
step-down
transformer
load
current
change
supply
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1
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asked
May 22, 2020
by
anonymous
State why a transformer always have an efficiency of more than 90%.
State why a transformer always have an efficiency of more than 90%.
Last answer:
As transformer is static device with no moving parts, the losses due to friction & windage are completely absent. Hence transformer has efficiency of more than 90%.
transformer
efficiency
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1
answer
asked
Apr 28, 2020
by
anonymous
Even at no-load, a transformer draws current from the mains. Why?
Even at no-load, a transformer draws current from the mains. Why?
even
at
no-load
a
transformer
draws
current
from
the
mains
why
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0
answers
asked
Aug 12, 2018
by
anonymous
Why Transformer rating is given in kVA?
Why Transformer rating is given in kVA?
Last answer:
1) The output of transformer is limited by heating due to the losses. Two types of losses in the transformer (i) Iron loss, (ii) Copper loss. 2) Iron loss depends on the transformer voltage (V). ... by load power factor. - Hence the transformer output is expressed in VA or kVA and not in kW.
transformer
rating
kva
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2.7k
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4
answers
asked
Dec 9, 2017
by
anonymous
Can transformer convert AC to DC?
Can transformer convert AC to DC?
Last answer:
No, Transformer cannot convert AC to DC.
transformer
convert
ac
dc
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2.9k
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9
answers
asked
Apr 27, 2020
by
anonymous
Explain the procedure to perform Short Circuit test on single phase transformer with circuit diagram.
Explain the procedure to perform Short Circuit test on single phase transformer with circuit diagram.
explain
the
procedure
to
perform
short
circuit
test
on
single
phase
transformer
with
diagram
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0
answers
asked
Sep 5, 2018
by
anonymous
Compare RC coupled, transformer coupled and direct coupled amplifier based on four points.
Compare RC coupled, transformer coupled and direct coupled amplifier based on four points.
Last answer:
Parameter RC coupled Transformer coupled Direct coupled Coupling element Resistor and capacitor Transformer No element Impedance matching Poor Excellent good Frequency ... Low frequency amplifier,opamp Size and cost small Large and bulky least
rc
coupled
transformer
direct
amplifier
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1.5k
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1
answer
asked
May 8, 2018
by
anonymous
The transformer works on the principle of:
The transformer works on the principle of: (A) Mutual induction (B) Mutual capacitance (C) All of the above (D) None of the above
Last answer:
The transformer works on the principle of: Mutual induction
transformer
works
principle
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58
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1
answer
asked
May 8, 2018
by
anonymous
Increasing the number of turns of wire on the secondary of a transformer will
Increasing the number of turns of wire on the secondary of a transformer will (A) Decrease the secondary current (B) Increase the primary current (C) Have no effect on the secondary current (D) Increase the secondary current
Last answer:
Increasing the number of turns of wire on the secondary of a transformer will Decrease the secondary current
increasing
number
turns
wire
secondary
transformer
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507
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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
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 excessive (B) 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
power
transformer
designed
operation
frequency
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485
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1
answer
asked
May 22, 2020
by
anonymous
Explain the effect of Harmonics on the Transformer.
Explain the effect of Harmonics on the Transformer.
Last answer:
Effect of Harmonics on the Transformer: 1. Core loss: Harmonic voltage increases the hysteresis and eddy current losses in the lamination. The amount of the core loss depends on ... small core vibrations. 5. Saturation problem: Sometimes additional harmonic voltage causes core saturation.
harmonics
transformer
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1
answer
asked
Apr 27, 2020
by
anonymous
Explain the open delta (delta-delta) test on transformer.
Explain the open delta (delta-delta) test on transformer.
open
delta
delta-delta
test
transformer
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0
answers
asked
Mar 19, 2018
by
anonymous
In a transformer the tappings are generally provided on?
Last answer:
In a transformer, the tappings are generally provided on low voltage side.
transformer
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53
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1
answer
asked
Mar 19, 2018
by
anonymous
The size of a transformer core will depend on?
The size of a transformer core will depend on?
Last answer:
The size of a transformer core will depend on frequency and area of the core.
size
transformer
core
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64
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1
answer
asked
Mar 19, 2018
by
anonymous
An open-circuit test on a transformer is conducted primarily to measure?
An open-circuit test on a transformer is conducted primarily to measure?
Last answer:
The open-circuit test in a transformer is used to measure
open-circuit
test
transformer
conducted
primarily
measure
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271
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2
answers
asked
Mar 19, 2018
by
anonymous
A no-load test is performed on a transformer to determine?
A no-load test is performed on a transformer to determine?
Last answer:
A no-load test is performed on a transformer to determine magnetizing current and loss.
no-load
test
transformer
determine
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84
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1
answer
asked
Mar 19, 2018
by
anonymous
If a transformer is switched on to a voltage more than the rated voltage?
If a transformer is switched on to a voltage more than the rated voltage?
Last answer:
If a transformer is switched on to a voltage more than the rated voltage its power factor will deteriorate.
transformer
switched
voltage
rated
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70
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1
answer
asked
Mar 19, 2018
by
anonymous
Sumpner's test is conducted on transformer to determine?
Sumpner's test is conducted on transformer to determine?
Last answer:
Sumpner's test is conducted on transformer to determine temprature.
sumpners
test
conducted
transformer
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92
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1
answer
asked
Apr 11, 2018
by
anonymous
To enable dc series motor work satisfactory with an AC supply, the following modifications should be done...
To enable dc series motor work satisfactory with an AC supply, the following modifications should be done (1) The yoke and poles should be completely laminated (2) The poles should be made of laminated steel (3) The air gap between stator and rotor be reduced (4) Compensating poles should be introduced
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133
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0
answers
asked
Feb 24, 2018
by
Amit Sharma
How IGBT convert DC into AC in solar inverter?
Last answer:
Igbt alone cant convert dc to ac. igbt half bridge or full bridge or three phase topology could be used to convert dc to ac. also igbt gates should be driven by microcontroller or pwm/spwm gate driving signals ... e4(-) and g4 c2e1 and c4e3 pins are AC output pins. its name is igbt inverter.
ac
dc
convert
transformer
solar
inverter
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162
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1
answer
asked
Mar 19, 2018
by
anonymous
Star/star transformers work satisfactorily when?
Last answer:
Star/star transformers work satisfactorily when load is balanced .
transformer
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71
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1
answer
asked
Aug 21, 2019
by
anonymous
when charging a battery we use a DC supply but not an AC supply. Why ?
when charging a battery we use a DC supply but not an AC supply. Why ?
Last answer:
When power is supplied to the battery, electrolyte inside the battery is divided into positive and negative ions, where ions with similar pole is gained in one side. This reactionʼs flow coincides with direct current.
charging
battery
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79
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1
answer
asked
Aug 12, 2019
by
anonymous
Why the Led Glow in Dc Supply ? Whenever give the Ac Supply What is Affect in Led ?
Why the Led Glow in Dc Supply ? Whenever give the Ac Supply What is Affect in Led ?
Last answer:
LEDs consume DC current to produce light; with AC current the LED will only be lit when current flow is in the proper direction. AC applied to an LED will cause it to blink on and off, and at high frequency the LED will appear to be lit continuously.
led
glow
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58
views
1
answer
asked
Aug 27, 2019
by
anonymous
What is the back E.M.F in Transformer ?
What is the back E.M.F in Transformer ?
Last answer:
Back emf in transformer is when apply voltage in primary side of transformer. This voltage produce flux according to Faraday law electro magnetic induction. This flux called mutual flux and this ... secondary flux oppos the applied voltage according to lenz law. its called back emf of transformer
transformer
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118
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1
answer
asked
Aug 22, 2019
by
Iqrima
Transformer is 180 degree phase shifting device.pls explain
transformer
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101
views
0
answers
asked
Aug 19, 2019
by
anonymous
transformer coupled amplifier
transformer coupled amplifier
Last answer:
transformer coupled amplifier
transformer
coupled
amplifier
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51
views
1
answer
asked
Jun 29, 2019
by
anonymous
What is auto transformer
transformer
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59
views
0
answers
asked
Jun 11, 2019
by
anonymous
Transformer efficiency
Transformer efficiency
Last answer:
Transformer efficiency
transformer
efficiency
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63
views
1
answer
asked
Sep 14, 2018
by
anonymous
Explain construction and working of isolation transformer.
Explain construction and working of isolation transformer.
Last answer:
Isolation Transformer https://youtu.be/gq9kjLlhPN0
isolation
transformer
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622
views
3
answers
asked
Sep 14, 2018
by
anonymous
Write selection criteria of distribution transformer with any four points.
Write selection criteria of distribution transformer with any four points.
Last answer:
Selection Criteria for Distribution Transformer: i) Ratings - The kVA ratings should comply with IS:2026 ( Part l )-1977*. The noload secondary voltage should be 433 volts for transformers to be ... is not necessary. vi) Cooling - The transformers covered in this group are generally ONAN, AN
criteria
distribution
transformer
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164
views
2
answers
asked
Sep 6, 2018
by
anonymous
Write any four advantages of instrument transformer.
Write any four advantages of instrument transformer.
Last answer:
Advantages of instrument transformer: 1. Extension of instrument range is possible. 2. Isolation of instruments from high voltage side. 3. Power loss is less as compared to shunts and multipliers. 4 ... measurement. 5. It is economical method of range extension. 6. Increases in safety of operator.
advantages
instrument
transformer
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1
answer
asked
Sep 6, 2018
by
anonymous
State the advantages of instrument transformer in using for extension of range of meters.
State the advantages of instrument transformer in using for extension of range of meters.
Last answer:
Advantages of instrument transformer: 1. Extension of instrument range is possible. 2. Isolation of instruments from high voltage side. 3. Power loss is less as compared to shunts and multipliers. 4 ... measurement. 5. It is economical method of range extension. 6. Increases in safety of operator.
advantages
instrument
transformer
extension
range
meters
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41
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1
answer
asked
Sep 1, 2018
by
anonymous
Introduction to transformer
Introduction to transformer
Last answer:
.embed-container { position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden; max-width: 100%; } .embed-container iframe, .embed-container object, .embed ... power start transformer, autotransformer, multiphase transformer, magnetic flux linkage transformer, resonant transformer etc.
introduction
transformer
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56
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1
answer
asked
Jul 14, 2018
by
Raldji
Deisign and simulation of 50 K.V.A Transformer 11/0.415kV using MATLAB or EM works
MATLAB design code and model description.
transformer
delta-star
amorphous
modelling
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63
views
0
answers
asked
May 8, 2018
by
anonymous
Cylindrical type transformer has:
Cylindrical type transformer has: (A) Single magnetic circuit (B) Double magnetic circuit (C) All of the above (D) None of the above
Last answer:
Cylindrical type transformer has: Single magnetic circuit
cylindrical
type
transformer
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78
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1
answer
asked
May 8, 2018
by
anonymous
The rating of transformer may be expressed in ____________.
The rating of transformer may be expressed in ____________. (A) kVAR (B) kW (C) kVA (D) Horse power
Last answer:
The rating of transformer may be expressed in kVA .
rating
transformer
expressed
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344
views
1
answer
asked
May 8, 2018
by
anonymous
Which of the following 3-phase connection of a transformer causes interference with the
Which of the following 3-phase connection of a transformer causes interference with the neighbouring communication lines: (A) Delta-Star (B) Star-Delta (C) Delta-Delta (D) Star-Star
Last answer:
Which of the following 3-phase connection of a transformer causes interference with the neighbouring communication lines: Star-Star
3-phase
connection
transformer
interference
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116
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1
answer
asked
May 8, 2018
by
anonymous
Which of the following does not change in a transformer?
Which of the following does not change in a transformer? (A) Current (B) Voltage (C) Frequency (D) All of the above
Last answer:
Which of the following does not change in a transformer? (A) Current (B) Voltage (C) Frequency (D) All of the above
change
transformer
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658
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1
answer
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