INDUCTION MOTORS 87 



(b) What is the power developed by each motor? 



(c) What are the effective resistance losses in the stator and 

 rotor of each motor? 



(d) What are the core losses in the stator and rotor of each 

 motor? 



66. The two induction motors, K and L, are connected in 

 concatenation. The stator of the first receives power at its 

 rated voltage and frequency, and the stator of the second is 

 short-circuited. Neglect the no-load component of the current. 

 Assume that the loss caused by the leakage flux is proportional 

 to the frequency and the square of the current. Assume that 

 the core loss due to the mutual flux varies as the frequency and 

 the square of the flux density. 



(a) What is the total output when the slip of the second motor 

 is 1.55 per cent.? 



(b) What is the power developed by each motor? 



(c) What are the effective resistance losses in the stator and 

 rotor of each motor? 



(d) What are the core losses in the stator and rotor of each 

 motor? 



67. The two induction motors, M and P, are connected in 

 concatenation. The stator of the first receives power at its 

 rated frequency, and the stator of the second is short-circuited. 

 Do not neglect the no-load component of the current, but assume 

 that it is proportional and wattless with respect to the generated 

 voltage. Assume that the loss caused by the leakage flux varies 

 as the frequency and the square of the current. Assume that 

 the core loss due to the mutual flux varies as the product of the 

 frequency and the square of the flux density. 



(a) What is the total output when the speed is 268 rev. per 

 in in. and the voltage generated by the air-gap flux in the rotor 

 winding of the second motor is 68 volts per phase? 



(b) What power do they receive from the line and at what 

 power factor do they operate? 



(c) What is the puwn- developed by each motor? 



68. The t\\o induction motors, K and L, are connected in 

 concatenation. I h stator of the first receives power at its 

 rated frequency, and the stator of the second is short-circuit .-,1. 

 Do not neglect the no-load component of the currrent, but assume 

 that it is proportional and wattless with respect to the generated 

 voltage. Assume that the loss caused by the leakage flux varies 



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