Worksheets141 S2A
Total questions: 10
Worksheet time: 20mins
Name
Class
Date
1.
In the synchronous speed formula, what does "Frequency" represent?
a)
A) The number of motor poles
b)
B) The motor's rated voltage
c)
C) The power factor of the motor
d)
D) The supply frequency in Hertz (Hz)
2.
How many poles does a 3-phase AC induction motor typically have?
a)
A) 1 pole
b)
B) 2 poles
c)
C) 3 poles
d)
D) The number of poles can vary depending on the motor design
3.
If a 3-phase motor has 4 poles and is connected to a 60 Hz power supply, what is its synchronous speed (Ns)?
a)
A) 1500 RPM
b)
B) 1800 RPM
c)
C) 3600 RPM
d)
D) 4800 RPM
4.
What is the relationship between the actual motor speed (N) and the synchronous speed (Ns) of a 3-phase AC induction motor?
a)
A) N = Ns - 120
b)
B) N = Ns + 120
c)
C) N = Ns / 120
d)
D) N = Ns x 120
5.
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)
A) 0.05
b)
B) 0.1
c)
C) 0.15
d)
D) 0.20
6.
What does the term "slip" refer to in the context of 3-phase AC induction motors?
a)
A) The rotational speed of the motor
b)
B) The difference between synchronous speed and actual speed
c)
C) The number of motor poles
d)
D) The motor's power factor
7.
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)
A) 4%
b)
B) 6%
c)
C) 8%
d)
D) 10%
8.
What happens to the slip of a 3-phase AC induction motor as the load on the motor increases?
a)
A) The slip decreases
b)
B) The slip remains constant
c)
C) The slip increases
d)
D) The slip becomes negative
9.
Which of the following factors primarily determines the speed of a 3-phase AC induction motor?
a)
A) Voltage
b)
B) Current
c)
C) Frequency
d)
D) Number of windings
10.
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)
A) 0.05
b)
B) 0.1
c)
C) 0.15
d)
D) 0.20
100 %
