DC Motor MCQs Part 1
Contents
- 1 A DC Motor converts
- 2 Carbon brushes are preferable over copper brushes since
- 3 The speed of a which type of DC motor is practically constant
- 4 The greatest percentage of power loss in DC motor is due to
- 5 The demand for large increase in torque of a DC. series motor is met by
- 6 Speed control by variation of field flux results in
- 7 Running speed of DC series motor is determined from
- 8 The speed of DC motor is
- 9 DC motors are still used in industrial applications since they
- 10 Armature reaction in DC motor is increased
A DC Motor converts
A DC Motor converts:
- DC power to AC power
- DC to Mechanical Power
- Mechanical Power to DC
- AC power to DC power
Correct answer: 2. DC to Mechanical Power
Carbon brushes are preferable over copper brushes since
Carbon brushes are preferable over copper brushes since:
- They have longer life
- They reduce sparking
- They reduce armature reaction
- They have lower resistance
Correct answer: 2. They reduce sparking
The speed of a which type of DC motor is practically constant
The speed of a which type of DC motor is practically constant
- Cumulatively compounded DC Motor
- Differentially compounded DC Motor
- Shunt DC Motor
- Series DC Motor
Correct answer: 3. Shunt motor
The greatest percentage of power loss in DC motor is due to
The greatest percentage of power loss in DC motor is due to:
- Core loss
- Windage loss
- Friction loss
- Copper loss
Correct answer: 4. Copper loss
The demand for large increase in torque of a DC. series motor is met by
The demand for large increase in torque of a DC. series motor is met by:
- Large decrease in current
- Small decrease in speed
- Large decrease in speed
- Large increase in speed
Correct answer: 3. Large decrease in speed
Speed control by variation of field flux results in
Speed control by variation of field flux results in:
- Constant power drive
- Variable torque drive
- Constant torque drive
- Variable power drive
Correct answer: 1. Constant power drive
Running speed of DC series motor is determined from
Running speed of DC series motor is determined from
- Load
- Field excitation
- Armature resistance
- None of these
Correct answer: 1. Load
The speed of DC motor is
The speed of DC motor is:
- Inversely proportional to flux per pole
- Directly proportional to flux per pole
- Inversely proportional to applied voltage
- None of these
Correct answer: 1. Inversely proportional to flux per pole
DC motors are still used in industrial applications since they
DC motors are still used in industrial applications since they:
- Are cheap
- Provide fine speed control
- Are simple in construction
- None of these
Correct answer: 2. Provide fine speed control
Armature reaction in DC motor is increased
Armature reaction in DC motor is increased
- When the armature current decreases
- When the field current increases
- When the armature current increases
- By interpoles
Correct answer: 3. When the armature current increases