Electric Machine Daily Quiz #10

Dynamic braking is also known as-

1. counter current braking

2. rheostatic braking

3. Leonard braking

4. All

Max speed that can be increased upto by field control is-

1. 2 times rated

2. 4 times rated 

3. 1/2 times rated

4. 1/4 times rated

The methods of braking with least and max efficiency respectively are-

1. Armature voltage control, Armature resistance control

2. Armature resistance control, Armature voltage control

3. Field Control, Armature voltage control

4. Armature voltage control, Field Control

A dc machine operating under rated speed is-

1. a constant power drive

2. a constant torque drive

3. both A, B

4. none

A dc machine operating above rated speed is-

1. a constant power drive

2. a constant torque drive

3. both A, B

4. none

Rotation in reverse direction is fulfilled by-

1. Armature resistance control

2. Field control

3. Ward Leonard control

4. Sumpner control

Swinburne's test is not performed on-

1. series motor

2. shunt motor

3. differential motor

4. seperately excited motor