A $3-$phase induction motor runs at almost $1,200$ rpm at no$-$load and $1,140$ rpm at full

load when supplied with power from a $60$ Hz$,3-$phase line.

a$)$ How many poles does the motor have?

b$)$ What is the percent slip at full load?

c$)$ What is the corresponding frequency of the rotor voltages?

d$)$ What is the corresponding speed $($i$)$ of the rotor field with respect to the rotor? $($ii$)$ of

the rotor field with respect to the stator? $($iii$)$ of the rotor field with respect to the stator

field?

e$)$ What speed would the rotor have at a slip of $10$ percent?

f$)$ What is the rotor frequency at this speed