Electrical Machines
The residual magnetism of a self-excited dc generator is lost. To build up its emf again

 the field winding connection must be reversed
 field winding must be excited by low voltage dc supply
 the armature connection must be reversed
 the field winding must be replaced

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Electrical Machines
Two 3-phase AC generators are such that one has twice the linear dimensions of the other. The field windings of each are excited to give identical sinusoidal air-gap flux density waveform. Both have the same number of stator slots and identical winding patterns. The conductor/slot in a big generator is K times that of the smaller one. The value of K to get equal no load voltage at same frequency is

  1/2.
 4.
 1/4.
 8.

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Electrical Machines
Which is the arrangement of windings in a core type single phase transformer?

 Lv on one core limb and hv on the other
 Half hv inside and half lv outside on each core limb
 Sandwiched lv and hv discs on each core limb
 Half lv inside and half hv outside on each core limb

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