SLIP

[searley]

If a 50hz ac motor has a synchronous speed of 750rpm.

How many poles will it have ?

4 pairs = 8

is there a bit of a trick in this question ?

Lecturer said he seen it in a g&g exam paper.

 

[Andy™]

If a 50hz ac motor has a synchronous speed of 750rpm.How many poles will it have ?

4 pairs = 8

is there a bit of a trick in this question ?

Lecturer said he seen it in a g&g exam paper.

3000/750 = 4. so 4 pairs. double for no. poles. 8

(assuming 100% efficiency)

main thing to watch for is poles and pairs of poles