Answer / sankaranarayanan

field flux produced by dc supply is constant where as in ac
supply will not give a constant field flux

So, alternator output will not constant.

Answer / kj

When a wire is moved through a magnetic field it produces a
voltage across the wire. To produce an ac output the wire
must move past a north pole and then a south pole in
continuing sequence.
A dc voltage on the field will maintain the poles with the
same polarity. An ac voltage will cause the polarity to
reverse 100 times a second (50Hz) and this will not be
usable for generating the ac output voltage.
Usually an ac voltage is used but it is rectified either as
half wave or full wave before being put into the field.

Answer / mohamed abd el-raouf

so the magnetic field of the rotor can connect with the magnetic field of the stator

Answer / haytham hashim

coz dc can be controlled in awide range but cann't be

when we switch on the switch and load is not connected at home,is electricity wasted?

1 Answers  

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What should be setting for alarm,tripping and cooling fan on for power transformer's oil temp. and winding temp. indicator?

0 Answers  

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WHAT IS LINE TRAP,HOW IS IT FUNCTION?

1 Answers   L&T,

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if the length, number of turns and area of coil are doubled then inductance of the coil becomes.?

1 Answers  

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what you mean by vector group of a 3 ph transformer

1 Answers  

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What is the difference between the relay and the circuit breaker?

0 Answers  

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Is it possible that Generator trip but Turbine not trip.Give explanation.

1 Answers   Essar,

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I know during Surge Impedance Loading maximum power is transferred through a transmission line and also Sending end voltage becomes equal to Receiving end voltage i.e Vs=Vr so my question is if both end voltages are equal then how current travels in such line hence how power is transmitted because flow of current needs Potential difference??

3 Answers   NTPC,

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How power cable & control cable can be differentiate from each other ?explain?

14 Answers   Aster, Finolex, TCE,

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What is PIR (pre inserting resistance) in 400kv EHV SF6 BREAKER? Why it use?

1 Answers   Adani,

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whow we find out dc motor field aur armature resistance

1 Answers  

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wat is the function of an inductor? examples.....

4 Answers  

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