Consider Figure 2 and Figure 3 to answer the following: 1. What is synchronous speed of the motor in Figure 2? 2. The operation of the motor in the part of the curve to the left of Point K in Figure 2 is considered unstable while to the right of it is stable; explain why that is. 3. Extend Figure 2 to include the generation operation of an induction machine. 4. Can we obtain the curves of Figure 3 in Squirrel cage induction motor (SCIM) or Wound rotor induction motor (WRIM)? Explain. 200 150 Tm(n) 100 50 K 0 0 200 400 600 800 1000 1200 1400 1600 1800 n Figure 2 Torque-Speed characteristics of an induction motor of rated torque 400 300 200 100 R3 R4 r4 R2 R1 60 20 40 80 % of synchronous speed Figure 3 Torque-Speed curves of an induction motor 100