Speed control by Ward Leonard method gives uniform speed variation_____________?
A. in one direction
B. in both directions
C. below normal speed only
D. above normal speed only
The hysteresis loss in a D.C. machine least depends on____________?
A. Frequency of magnetic reversals
B. Maximum value of flux density
C. Volume and grade of iron
D. Rate of flow of ventilating air
A direct on line starter is used: for starting motors___________?
A. up to 5 H.P
B. up to 10 H.P
C. up to 15 H.P
D. up to 20 H.P
If a D.C. motor is to be selected for conveyors, which rriotor would be preferred ?
A. Series motor
B. Shunt motor
C. Differentially compound motor
D. Cumulative compound motor
In which of the following applications D.C. series motor is invariably tried?
A. Starter for a car
B. Drive for a water pump
C. Fan motor
D. Motor operation in A.C. or D.C
In the D.C. motor the iron losses occur in____________?
A. the field
B. the armature
C. the brushes
D. the commutator
The type of D.C. motor used for shears and punches is_____________?
A. shunt motor
B. series motor
C. differential compoutid D.C. motor
D. cumulative compound D.C. motor