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

Is there possible to Test Transformer for Overfluxing Capability. Or is there any firm who does Overfluxing Test on Transformer?

0 Answers  

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a 3 phase slip ring induction motor is wound for 4 poles on stator and 6 poles on rotor; when 3 phase balanced voltage source at 50 hz is applied to motor it will run at a)1500rpm b)1000rpm c)750 rpm d)zero rpm

13 Answers   Essar, PSPCL, PSTCL,

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what is defference by mcb,mccb and mpcb

4 Answers   Bhel,

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advantages & disadvantages of Lagging and leading power factor .

0 Answers   KMSC,

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a 120 60 watt incandescent lamp has to be operated from 50 c/sec 1 phase ac supply. in order to do this a circuit element has to be connect in series with the lamp. which one of the following sries element is preferable.

1 Answers   SSC,

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what is the minimum requirement gigaohms for the insulation test using 5kv in 300mm xlpe cable

0 Answers  

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Please send 110 kv sb station full single line drawing(sld)

0 Answers  

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why a tester wont shock while testing the power in house

0 Answers   Tessolve,

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what is the use of reactive power

3 Answers  

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calculation of knee point voltage of current transformer?

2 Answers   TATA,

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last week we did the REF relay test by closing single pole (R phase) of CB and apply 380V at the primary of delta transformer. we get 33A at the primary of the R phase star end. but we get 380A at both R an B in delta side. how and why?

1 Answers   Siemens,

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power generation unit kw/hr or kw/day ?? please answer me engr_kalam@yahoo.com

3 Answers  

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