Electrical Engineering Quiz

A shunt-wound motor is the one which has:

• two field windings

• one field winding connected in parallel with the armature winding

• one field winding connected in series with the armature winding

A transformer is a device which converts:

• alternating current into direct current

• mechanical energy into electrical energy

• the alternating current of one voltage into the alternating current of another voltage but of the same frequency

Stepless speed regulation within wide limits is accomplished by putting:

• an additional resistor in the armature

• a regulating rheostat in the armature circuit

• both a regulating rheostat and an additional resistor in the armature circuit

The operating principle of transformers is based upon the phenomenon of:

• self-induction

• electric induction

• mutual induction

The starting torque of the shunt-wound motor is:

• small, directly proportional to the armature current square value

• large, proportional to the square value of the armature current

• considerable, inversely proportional to the armature current

The ends of the three-phase transformer windings of upper voltage are marked by:

• the small letters a,b,c

• the capitals A,B,C

• the capitals X,Y,Z

A series-wound motor is one which:

• doesn't tend to overspeed while running idle

• doesn't tend to overspeed while running at load which is 20-25% less than the rated one

• tends to overspeed while running idle or at load which is 20-25% less than the rated one

An autotransformer possesses:

• one winding which is primary and secondary at the same time

• many windings

The speed characteristic of a series-wound motor makes:

• a slightly inclined curve

• a considerably inclined curve

• a straight line

The efficiency of an autotransformer in comparison with that of an ordinary transformer of the same power is:

• lower

• absolutely the same

• higher