Rotating Amplifiers - GATE EE Electrical Machines Free MCQ Test with solutions

The rotating amplifiers are applicable in feedback systems giving large amplified outputs.

The rotating amplifiers have stable transient conditions, which makes them favourable to use in high power sectors.

The sluggish transient response of the ordinary dc machines makes them inappropriate to use them in amplidynes.

Yes, the reaction mmf of the first stage is made to act as field flux for second stage to have faster transient response.

The cross field machines have two fluxes electrically in quadrature.

There are two stages for flux generators in order to have faster response in the system.

Metadyne is negative feedback with respect to main current flowing in the second stage set of motors.

The d-flux is neutralized by compensating winding at all possible loads as the same flux will be produced but in the opposite direction so as to cancel the flux.

 The resultant d-axis flux lies along the main field poles and are so field flux. The d- axis is completely under the control of field winding and is unaffected by direct axis current.

Amplidynes find applications in feedback systems with large power handling requirements.

 Interpoles nullify armature cross magnetizing flux and the reactance voltage. So it is more than the armature mmf for a good efficient machine.

The commutation in dc machines is delayed because of the emf induced in the coils and the mutual interaction of the field with neighbour coils.

Differentially compounded generators are used for welding purposes, not motors.

DC compound generators are used for maintaining constant voltage across the terminals.

Dc shunt motor is almost constant speed generator and thus its voltage regulation is very good than all and differential compound generator has most poor v.r.