**Answer is:**

### 1000 R.P.M.

**Explanation:**

Speed of 2 Pole Motor

Ns=(120 x Frequency)/Number of Poles

Ns=(120×50)/2=3000 RPM

Speed of 4 Pole Motor

Ns=(120 x Frequency)/Number of Poles

Ns=(120×50)/4=1500 RPM

Speed of 8 Pole Motor

Ns=(120 x Frequency)/Number of Poles

Ns=(120×50)/8=750 RPM

**Answer is:**

### 12

**Answer is:**

### by increasing the rotor resistance

**Answer is:**