## Quiz sheet for motors

DC compound motors are usually connected to be __________ compounded.

A) cumulatively

B) differentially

C) shunt

D) series

ANSWER: A

If the load on a DC motor is decreased, the speed will

A) increase

B) be unaffected

C) also decrease

D) not change

ANSWER: A

The copper losses in the armature:

A) increase in proportion to armature current squared

B) decrease as load increases

C) are constant at any load

D) increase in proportion to armature current

ANSWER: A

The force acting on a conductor is directly proportional to the

A) Strength of the magnetic field

B) cross sectional area af the conductor

C) angle of incidence of the flux

D) radius of the drive shaft

ANSWER: A

The force acting on a conductor is proportional to the

A) length of the conductor

B) cross sectional area af the conductor

C) angle of incidence of the flux

D) radius of the drive shaft

ANSWER: A

The force acting on a conductor is directly proportional to the

A) current in the conductor

B) cross sectional area af the conductor

C) angle of incidence of the flux

D) radius of the drive shaft

ANSWER: A

The motor most suited to a relatively constant speed drive operating on intermittent heavy loading would be:

A) cumulatively compounded motor

B) shunt motor

C) series motor

D) differential motor

ANSWER: A

The torque of a shunt motor for a given value of field flux:

A) is directly proportional to the armature current

B) is inversely proportional to armature current

C) varies as the square of the current

D) remains constant

ANSWER: A

To reverse the direction of rotation of a compound motor by field reversal, you would reverse the connection to:

A) both the shunt and series fields

B) either the shunt or series field

C) the series field only

D) the shunt field only

ANSWER: A

When motors are operating normally on load, the armature current is limited by:

A) back e.m.f.

B) main field strength

C) armature resistance

D) supply voltage

ANSWER: A

Last modified: Tuesday, 1 June 2021, 9:16 AM