Torque of motor varies as the cube of the speed means what?

In summary, torque is a measure of rotational force and is typically measured in newton-meters or pound-feet. When the torque of a motor varies, it means that it can fluctuate based on factors like speed, load, or voltage. This variation is proportional to the speed cubed, meaning any change in speed will result in a much larger change in torque. This is due to the power law relationship between speed and torque, which is a result of the physics behind how motors work.
  • #1
Ahmedzica
14
0
is this means that torque is proportional or inversely proportional to the cube of speed

the problem says

The torque of a load driven by a 385-V, Dc shunt motor varies as the cube of the speed. The current taken by the motor is 51A at a certian speed. Calculate the additional resistance to be inserted in series with the armature to reduce the speed to 50 percent of the original value. The armature circuit resistance is 0.5 ohms and the field-circuit resistance is 35 ohms


Thanks
 
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  • #2
Torque is proportional to the cube of speed.
 
  • #3
Thanks alot!
 

FAQ: Torque of motor varies as the cube of the speed means what?

1. What is torque?

Torque is a measure of the force that can cause an object to rotate about an axis. It is typically measured in units of newton-meters (N*m) or pound-feet (lb*ft).

2. What does it mean for the torque of a motor to vary?

When the torque of a motor varies, it means that it can change or fluctuate depending on certain factors, such as speed, load, or voltage.

3. What does it mean for the torque of a motor to vary as the cube of the speed?

This means that as the speed of the motor increases, the torque will increase at a rate that is proportional to the speed cubed. For example, if the speed doubles, the torque will increase by a factor of 8 (2^3 = 8).

4. How is the cube of the speed related to torque?

The relationship between the cube of the speed and torque is a mathematical one, known as a power law. This relationship states that the torque is directly proportional to the speed cubed, meaning any change in the speed will result in a much larger change in the torque.

5. Why does the torque of a motor vary as the cube of the speed?

This relationship is a result of the physics behind how motors work. As the speed increases, the forces acting on the motor's components also increase, causing a larger change in torque. Additionally, the power output of a motor is directly proportional to the speed cubed, so the torque must also follow this relationship.

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