Starting torque
Operating speed
motor is increased, which of the following will decrease? A. Starting torque B. Operating speed C. Full-load current
All of the above
Answer is Right!
Answer is Wrong!
The correct answer is: D. All of the above
When the supply voltage for a D.C. motor is increased, the following will decrease:
- Starting torque: The starting torque of a D.C. motor is proportional to the square of the supply voltage. Therefore, if the supply voltage is increased, the starting torque will decrease.
- Operating speed: The operating speed of a D.C. motor is proportional to the supply voltage. Therefore, if the supply voltage is increased, the operating speed will decrease.
- Full-load current: The full-load current of a D.C. motor is proportional to the supply voltage. Therefore, if the supply voltage is increased, the full-load current will decrease.
The following is a brief explanation of each option:
- Starting torque: The starting torque of a D.C. motor is the torque that the motor produces when it is first turned on. The starting torque is important because it determines how easily the motor can start and how much load it can carry when it is first turned on. The starting torque of a D.C. motor is proportional to the square of the supply voltage. Therefore, if the supply voltage is increased, the starting torque will decrease.
- Operating speed: The operating speed of a D.C. motor is the speed at which the motor runs when it is under load. The operating speed is important because it determines how fast the motor can turn and how much work it can do. The operating speed of a D.C. motor is proportional to the supply voltage. Therefore, if the supply voltage is increased, the operating speed will decrease.
- Full-load current: The full-load current of a D.C. motor is the current that the motor draws when it is running at full load. The full-load current is important because it determines how much power the motor needs and how much heat it will generate. The full-load current of a D.C. motor is proportional to the supply voltage. Therefore, if the supply voltage is increased, the full-load current will decrease.