Final answer:
The number of poles on the machine is 4.
Step-by-step explanation:
The number of poles on a 3-phase induction motor can be determined by using the formula:
P = (120 x f) / Ns
where P is the number of poles, f is the frequency of the supply, and Ns is the synchronous speed in rpm. In this case, the motor is running at 24 revls (revolutions per second) with a slip of 4% on a 50 Hz supply.
Therefore, the synchronous speed can be calculated as:
Ns = 120 x f / P
Substituting the given values, we have:
Ns = 120 x 50 / 4 = 1500 rpm
Now, substituting the values of Ns and f into the first formula, we can solve for P:
P = (120 x 50) / 1500 = 4 poles
Therefore, the total number of poles on the machine is 4.