Which motor should not be started on no-load ?

The speed of a D.C. shunt motor is required to be more than full load speed. This is possible by______________?

A. reducing the field current
B. decreasing the armature current
C. increasing the armature current
D. increasing the excitation current
E. none of the above methods

In a manual shunt motor starter?

A. over load relay is connected in series and no volt relay in parallel with the load
B. over load relay is connected in parallel and no volt relay in series with the load
C. over load relay and no volt relay are both connected in series with the load
D. over load relay and no volt relay are both connected in parallel with the load

The speed of a motor falls from 1100 r.p.m. at no-load to 1050 r.p.m. at rated load. The speed regulation of the motor is______________?

A. 2.36%
B. 4.76%
C. 6.77%
D. 8.84%

Which of the following law/rule can he used to determine the direction of rotation of D.C. motor ?

A. Lenz’s law
B. Faraday’s law
C. Coloumb’s law
D. Fleming’s left-hand rule

As there is no back e.m.f. at the instant of starting a D.C. motor, in order to prevent a heavy current from flowing though the armature circuit____________________?

A. a resistance is connected in series with armature
B. a resistance is connected parallel to the armature
C. armature is temporarily open circuited
D. a high value resistor is connected across the field winding

The ratio of starting torque to full-load torque is least in case of____________?

A. series motors
B. shunt motors
C. compound motors
D. none of the above