5 Questions
What is a synchronous motor and how does it differ from a DC motor?
A synchronous motor is an alternator that operates as a motor by connecting its armature winding to a 3-phase supply. It runs at synchronous speed, which is tied to the frequency of the source. Unlike a DC motor, its speed stays constant irrespective of the load or voltage of the 3-phase supply.
What is the relationship between synchronous speed and the frequency of the source?
The synchronous speed of a synchronous motor is directly proportional to the frequency of the source. It can be calculated using the formula Ns = 120f/P, where Ns is the synchronous speed, f is the frequency, and P is the number of poles.
Why are synchronous motors not commonly used?
Synchronous motors are not commonly used because they run at a constant speed, known as synchronous speed. This lack of speed variation limits their application in situations where variable speed control is required.
How can the speed of a synchronous motor be changed?
The speed of a synchronous motor can only be changed by varying the supply frequency. The formula Ns = 120f/P demonstrates that the synchronous speed is directly proportional to the frequency. Therefore, adjusting the frequency will alter the motor's speed.
What is one characteristic feature of synchronous motors?
One characteristic feature of synchronous motors is that they run at synchronous speed or not at all. Their speed remains constant at all loads, and the only way to change it is by adjusting the supply frequency.
Test your knowledge on synchronous motors and their operation as a motor. This quiz covers topics such as synchronous speed and the connection of armature winding to a 3-phase supply. Challenge yourself and see how well you understand the principles of synchronous motors.
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