Final answer:
When the speed of a DC motor increases, the resolution of speed measurement using an incremental encoder improves, as more pulses are generated per unit of time in the pulse-counting method, or the time interval between pulses decreases in the pulse-timing method.
Step-by-step explanation:
When the speed of a DC motor is increased from 10 to 100 rpm, and the speed is measured using an incremental encoder, there are two methods commonly used: the pulse-counting method and the pulse-timing method. To understand how the speed resolution changes with these methods, we need to know how the encoder works.
An incremental encoder generates a specific number of pulses per revolution (PPR). The pulse-counting method takes into account the number of pulses in a given time to determine the speed. As speed increases, the pulses per second increase, leading to higher resolution of speed measurement. With the pulse-timing method, the time between pulses is measured; when the speed increases, this time decreases, hence the speed resolution improves as there is less time between pulses.
Overall, an increase in speed results in an increase in the number of pulses counted in a fixed time or a decrease in the time interval between pulses, leading to improved speed resolution with both methods.