Question

When measuring fuel pump current using a lab scope, it is determined that eight commutator bumps (one revolution of the motor) occur every 10 milliseconds. This fuel pump is spinning at _________ RPM.

Answer 1

The fuel pump is spinning at a rate of 48,000 RPM.

Step-by-step explanation:

To determine the fuel pump's RPM, we need to convert the time period between each commutator bump into seconds. Given that eight commutator bumps occur every 10 milliseconds, we divide the time period by the number of commutator bumps to get the duration of each commutator bump. In this case, each commutator bump lasts 1.25 milliseconds (10 ms / 8). Next, we convert this duration into seconds by dividing it by 1000, which gives us 0.00125 seconds. Finally, we determine the RPM by dividing 60 seconds (to convert seconds into minutes) by the duration of each commutator bump in seconds. Therefore, the fuel pump is spinning at a rate of 48,000 RPM (60 seconds / 0.00125 seconds).