Magnetic field in a D.C. generator is produced by_______________?

A. Electromagnets
B. Permanent magnets
C. Both a. and b.
D. None of the above

The demagnetising component of armature reaction in a D.C. generator___________?

A. Reduces generator e.m.f.
B. Increases armature speed
C. Reduces interpoles flux density
D. Results in sparking trouble

Which of the following statement about D.C. generators is false ?

A. Compensating winding in a d.c. machine helps in commutation
B. In a d. c. generator interpoles winding is connected in series with the armature winding
C. Back pitch and front pitch are both odd and approximately equal to the pole pitch
D. Equilizing bus bars are used with parallel running of d.c. shunt gen¬erators

A D.C. welding generator has____________?

A. Lap winding
B. Wave moving
C. Duplex winding
D. Any of the above

In the case of lap winding resultant pitch is____________?

A. Multiplication of front and back pitches
B. Division of front pitch by back pitch
C. Sum of front and back pitches
D. Difference of front and back pitches

The function of pole shoes in the case of D.C. machine is______________?

A. To reduce the reluctance of the mag¬netic path
B. To spread out the flux to achieve uniform flux density
C. To support the field coil
D. To discharge all the above functions

For a D.C. machines laboratory following type of D.C. supply will be suitable___________?

A. Rotary converter
B. Mercury are rectifier
C. Induction motor d.c. generator set
D. Synchronous motor d.c. generator set

In case of D.C. machine winding, number of commutator segments is equal to______________?

A. Number of armature coils
B. Number of armature coil sides
C. Number of armature conductors
D. Number of armature turns

Welding generator will have____________?

A. Lap winding
B. Wave winding
C. Delta winding
D. Duplex wave winding

Equilizer rings are required in case armature is_______________?

A. Wave wound
B. Lap wound
C. Delta wound
D. Duplex wound