DM 2 Multiple-choice tasks

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Questions

Answer choice

  1

The DC motor is converted…

a) thermal energy into electrical energy;

b) electrical energy into thermal energy;

c) mechanical energy into electrical energy;

d) electrical energy into mechanical energy;

e) electrical energy into chemical energy.

2

Induced EMF and current are the same direction in …

a) DC motor;

b) DC generator;

c) in the transformer;

d) collector;

3

The anchor of the DC machine is called …

a) a stationary part of the machine DC;

b) rotating part of DC machine;

4

The part of the DC generator that provides AC rectification is …

a) frame;

b) collector;

c) in bearings;

d) excitation winding;

e) lead-out ends.

5

DC motor can be used as DC motor and Vice versa

a) not;

b) it is possible with alterations;

c) you can.

6

In traction DC electric machines are used exclusively …

a) carbon graphite brushes;

b) graphite brushes;

c) metallographic brushes;

d) electric brushes.

7

The cores of the main poles are recruited from separate sheets,

 electrical steel thickness of 0.35 – 0.5 mm, isolated from each other by a layer of insulation, in order to

 a) reduce the loss of electrical energy;

 b) reduce eddy current losses;

 c) increase of losses in the induction currents;

 d) convert electrical energy into mechanical energy.

8

The part of the core of the main pole facing the surface of the anchor is wider and is called …

a) additional pole;

b) excitation winding;

c) a pole piece;

d) collector;

e) brush holder.

9

The armature winding of the DC machine is made of …

a) from insulated copper wire or copper bus;

b) non-insulated steel wire;

c) made of insulated aluminum wire or steel tire.

d) of the collector plates.

10

The compensating winding improving working conditions of the collector and brushes have …

a) in brush holders;

b) in additional poles;

c) in the pole tips of the main poles;

d) at anchor DC machine;

e) on the collector of DC machine.