Level 3 301 Motor Questions

[Mikeymike77]

Hope this helps

1: When a capacitor start capacitor run motor reaches synchronous speed the centrifugal switch?

a: Leaves the start winding connected
b: Leaves only the run winding connected
c: Disconnected the supply to the start capacitor
d: Disconnects the run and start capacitors

2: For a three phase induction motor the differerence between the synchronous speed and rotor speed is the?
a: Slope
b: Slip
c: Skip
d: Slide

3: The rotational speed of a three phase, four pole synchronous motor operating at 50Hz supply.
a: 1500rpm
b: 3000rpm
c: 1000rpm
d: 750rpm

4: When a single phase capacitor start and capacitor run motor approaches its normal speed the centrifugal switch disconnects the?
a: Start capacitor
b: Run capacitor
c: Start winding
d: Run winding

5: The direction of a capacitor start motor can be reversed by?
a: Changing connections to both windings
b: Changing capacitor connections
c: Changing over the connections to the start or run winding
d: Changing connections to start & run winding

6: A single phase AC motor is constructed with?
a: Two magnetic fields in phase with each other
b: A magnetic field
c: Three magnetic fields
d: A secondary magnetic field out of phase with the primary field

7: A two pole induction motor runs at 925rpm when connected to the 50Hz supply. Calculate the slip?
a: 71%
b: 56.5%
c: 69%
d: 62%

8: A 3 phase 4 pole motor 50Hz induction motor has a slip of 4% the actual speed of the motor is?
a: 1500rpm
b: 1440rpm
c: 1400rpm
d: 1359rpm

9: Cage rotor induction motor are considered to be?
a: A variable speed machines
b: low speed
c: high speed
d: constant speed

10: Connections made to rotor windings on a 3 phase induction motor use?

a: Mutual inductance effect rotor & stator
b: Commutators and brushes
c: Capacitor link to rotor windings
d: Slip ring & brushes

11: The Thermal trip on a direct online starter (DOL) is to?
a: Provide magnetic overload protection
b: Provide thermal overload protection
c: Provide remote starting
d: Prevent motor over speed

12: A motor with a wound rotor has windings on?
a: Rotor only
b: Stator only
c: Stator & rotor
d: Communtator & field

13: When starting a 400v 3 phase cage rotor motor using star/delta starter, the voltage across each stator phase is?
a: 400v start 230v run
b: 133v start 230v run
c: 133v start 400v run
d: 230v start 400v run

14: A single loop of wire connected to the slip rings rotated in a magnetic field. Voltage
measured at slip rings will be?
a: D.C
b: A.C
c: undirectional
d: Intermittent

15: A capacitor start and run single phase induction motor runs as?
a: Quad phase motor
b: SIngle phase motor
c: Two phase motor
d: Three phase motor

16: Which of the following is suitable for starting a 3 phase rotor cage induction motor?
a: Auto transformer & rotor resistance
b: Rotor resistance and capacitor start
c: Auto transformer & star/delta
d: Capacitor start and star/delta

17: To reverse the rotation of a 3 Phase induction motor?

a: Disconnect the grey phase
b: Disconnect the brown phase
c: Change over any two phases
d: Change over three phases

 

[Guest123]

Are you after answers to this lot???

 

[Mikeymike77]

Well I had some spare time so though I'd pop them on since there's not much on motors. I have answers for some of the questions but welcome to opinions.

 

[Marvo]

bbaccdcba?badacac.

How did I do?

 

[Mikeymike77]

1: When a capacitor start capacitor run motor reaches synchronous speed the centrifugal switch?

a: Leaves the start winding connected
b: Leaves only the run winding connected
c: Disconnected the supply to the start capacitor
d: Disconnects the run and start capacitors

2: For a three phase induction motor the differerence between the synchronous speed and rotor speed is the?
a: Slope
b: Slip
c: Skip
d: Slide

3: The rotational speed of a three phase, four pole synchronous motor operating at 50Hz supply.
a: 1500rpm
b: 3000rpm
c: 1000rpm
d: 750rpm

4: When a single phase capacitor start and capacitor run motor approaches its normal speed the centrifugal switch disconnects the?
a: Start capacitor
b: Run capacitor
c: Start winding
d: Run winding

5: The direction of a capacitor start motor can be reversed by?
a: Changing connections to both windings
b: Changing capacitor connections
c: Changing over the connections to the start or run winding
d: Changing connections to start & run winding

6: A single phase AC motor is constructed with?
a: Two magnetic fields in phase with each other
b: A magnetic field
c: Three magnetic fields
d: A secondary magnetic field out of phase with the primary field

7: A two pole induction motor runs at 925rpm when connected to the 50Hz supply. Calculate the slip?
a: 71%
b: 56.5%
c: 69%
d: 62%

8: A 3 phase 4 pole motor 50Hz induction motor has a slip of 4% the actual speed of the motor is?
a: 1500rpm
b: 1440rpm
c: 1400rpm
d: 1359rpm

9: Cage rotor induction motor are considered to be?
a: A variable speed machines
b: low speed
c: high speed
d: constant speed

10: Connections made to rotor windings on a 3 phase induction motor use?

a: Mutual inductance effect rotor & stator
b: Commutators and brushes
c: Capacitor link to rotor windings
d: Slip ring & brushes

11: The Thermal trip on a direct online starter (DOL) is to?
a: Provide magnetic overload protection
b: Provide thermal overload protection
c: Provide remote starting
d: Prevent motor over speed

12: A motor with a wound rotor has windings on?
a: Rotor only
b: Stator only
c: Stator & rotor
d: Communtator & field

13: When starting a 400v 3 phase cage rotor motor using star/delta starter, the voltage across each stator phase is?
a: 400v start 230v run
b: 133v start 230v run
c: 133v start 400v run
d: 230v start 400v run

14: A single loop of wire connected to the slip rings rotated in a magnetic field. Voltage
measured at slip rings will be?
a: D.C
b: A.C
c: undirectional
d: Intermittent

15: A capacitor start and run single phase induction motor runs as?
a: Quad phase motor
b: Single phase motor
c: Two phase motor
d: Three phase motor

16: Which of the following is suitable for starting a 3 phase rotor cage induction motor?
a: Auto transformer & rotor resistance
b: Rotor resistance and capacitor start
c: Auto transformer & star/delta
d: Capacitor start and star/delta

17: To reverse the rotation of a 3 Phase induction motor?

a: Disconnect the grey phase
b: Disconnect the brown phase
c: Change over any two phases
d: Change over three phases

 

[BicMac]

I had several of these exact questions today on my 301, good stuff mate

 

[i=p/u]

im starting level 3 in september and i aint a clue about motors, sure il go through it all on level 3 before tests. is this the case guys???

 

[ExArmy]

10: Connections made to rotor windings on a 3 phase induction motor use?

a: Mutual inductance effect rotor & stator
b: Commutators and brushes
c: Capacitor link to rotor windings
d: Slip ring & brushes

13: When starting a 400v 3 phase cage rotor motor using star/delta starter, the voltage across each stator phase is?
a: 400v start 230v run
b: 133v start 230v run
c: 133v start 400v run
d: 230v start 400v run

are these 2 defo the right answers?

 

[ExArmy]

im starting level 3 in september and i aint a clue about motors, sure il go through it all on level 3 before tests. is this the case guys???

not if you go to my college! seriously, we've had 3 lessons on motors. i've got one more lesson and then my gola next week. it does seem odd theres alot of questions on motors in all the mock golas i've seen, yet we are cramming it all in last minute, and effectively we are just being told the basics what you need to pass the exam, not going in depth learning all about them which is what i'd prefer.

 

[topquark]

are these 2 defo the right answers?

I'd go for D for both of those mate.

 

[ExArmy]

I'd go for D for both of those mate.

yeah thats what i thought. where did you get these answers from mikeymke?

 

[Mikeymike77]

yeah thats what i thought. where did you get these answers from mikeymke?

Yes went through it with my tutor tuesday night.