Calculated Multiple-Choice Questions

A three-phase motor has 6 poles and operates at 50 Hz. Calculate the synchronous speed. Show all steps in your calculation.

• 1000 RPM

• 1200 RPM

• 1500 RPM

• 1800 RPM

If the synchronous speed of a 50 Hz motor is 1500 RPM and the rotor speed is 1470 RPM, calculate the percentage slip. Show your working for the slip formula.

• 1.33%

• 2.00%

• 2.33%

• 3.00%

A 4-pole motor operates at 60 Hz. Calculate the synchronous speed and show the formula you used. Provide all steps in your calculation.

• 1200 RPM

• 1500 RPM

• 1800 RPM

• 2400 RPM

A motor running at 96% of its synchronous speed has a synchronous speed of 1200 RPM. Calculate the rotor speed. Show your calculations step-by-step.

• 1152 RPM

• 1160 RPM

• 1175 RPM

• 1180 RPM

If a 50 Hz motor has 8 poles, calculate its synchronous speed. Show all working steps.

• 500 RPM

• 750 RPM

• 1000 RPM

• 1250 RPM

A 6-pole motor operates at 60 Hz. The rotor speed is 1150 RPM. Calculate the synchronous speed and the percentage slip. Provide all working steps for both the synchronous speed and slip calculations.

• 4.17%

• 4.44%

• 5.00%

• 5.50%

A motor has a slip of 3% and a synchronous speed of 1800 RPM. Calculate the rotor speed. Show all steps in your calculation.

• 1650 RPM

• 1700 RPM

• 1740 RPM

• 1760 RPM

For a three-phase motor with a rotor speed of 1440 RPM and a synchronous speed of 1500 RPM, calculate the percentage slip. Provide all the necessary working.

• 2.5%

• 3.0%

• 4.0%

• 5.0%

If a motor with a 4% slip runs at 1440 RPM, calculate its synchronous speed. Show your working for the calculation of synchronous speed based on slip.

• 1485 RPM

• 1500 RPM

• 1560 RPM

• 1600 RPM

A motor operates with a synchronous speed of 1500 RPM and a rotor speed of 1400 RPM. Calculate the slip percentage. Show all steps clearly.

• 5.33%

• 6.67%

• 7.5%

• 8.67%