141 S2A

In the synchronous speed formula, what does "Frequency" represent?

• A) The number of motor poles
• B) The motor's rated voltage
• C) The power factor of the motor
• D) The supply frequency in Hertz (Hz)

How many poles does a 3-phase AC induction motor typically have?

• A) 1 pole
• B) 2 poles
• C) 3 poles
• D) The number of poles can vary depending on the motor design

If a 3-phase motor has 4 poles and is connected to a 60 Hz power supply, what is its synchronous speed (Ns)?

• A) 1500 RPM
• B) 1800 RPM
• C) 3600 RPM
• D) 4800 RPM

What is the relationship between the actual motor speed (N) and the synchronous speed (Ns) of a 3-phase AC induction motor?

• A) N = Ns - 120
• B) N = Ns + 120
• C) N = Ns / 120
• D) N = Ns x 120

If a 3-phase motor has a synchronous speed (Ns) of 900 RPM and is running at an actual speed (N) of 850 RPM, what is its slip?

• A) 0.05
• B) 0.1
• C) 0.15
• D) 0.20

What does the term "slip" refer to in the context of 3-phase AC induction motors?

• A) The rotational speed of the motor
• B) The difference between synchronous speed and actual speed
• C) The number of motor poles
• D) The motor's power factor

If a 3-phase motor has a synchronous speed (Ns) of 1200 RPM and is running at an actual speed (N) of 1120 RPM, what is its slip percentage?

• A) 4%
• B) 6%
• C) 8%
• D) 10%

What happens to the slip of a 3-phase AC induction motor as the load on the motor increases?

• A) The slip decreases
• B) The slip remains constant
• C) The slip increases
• D) The slip becomes negative

Which of the following factors primarily determines the speed of a 3-phase AC induction motor?

• A) Voltage
• B) Current
• C) Frequency
• D) Number of windings

If a 3-phase motor has a synchronous speed (Ns) of 900 RPM and is running at an actual speed (N) of 850 RPM, what is its slip?

• A) 0.05
• B) 0.1
• C) 0.15
• D) 0.20