Energy Conversion

Two things which are same for primary and secondary of a transformer are

A transformer operates poorly at very low frequencies because

In auto transformer, the primary and secondary are _____ coupled.

A storage battery in which the plates consist of lead-antimony supporting grids covered with a lead oxide paste, immersed in weak sulfuric acid.

One of the following is a dry storage cell.

The field structure of a dc machine uses

Small dc machine generally have _____ poles.

The armature of a dc machine is laminated in order to reduce

The demand for a large increase in torque of a dc series motor is met by a

As the load increases, a _____ motor will speed up.

The flux in the core of a single-phase transformer is

When the primary of a transformer is connected to a dc supply,

A constant-source has

If the excitation of an alternator operating in parallel with other alternators is increased above the normal value of excitation, its

The synchronous reactance of an alternator is generally _____ armature resistance.

DC series motors are used in those applications where _____ required.

A dc motor is still used in industrial applications because it

The stator of an alternator is wound for _____ on the rotor.

Why are carbon brushes preferable compared to copper brushes?

The synchronous reactance of an alternator _____ as the iron is saturated.