# Variables
P = 4.; #no. of poles
f = 50; #Hz
S = 4./100; #slip
N = 600; #rpm
p = P/2; #pair of poles
# Calculations and Results
#(a)
Ns = 60*f/p; #rpm(Synchronous speed)
print "(a) Synchronous speed(rpm) : %.2f"%Ns
#(b)
Nr = Ns-S*Ns; #rpm(Rotor speed)
print "(b) Rotor speed(rpm) : %.2f"%Nr
#(c)
Sdash = (Ns-N)/Ns; #per unot slip
fr = f*Sdash; #Hz(Rotor frequency)
print "Rotor frequency(Hz) : %.2f"%fr
import math
# Variables
Zs = 240.; #no. of conductors in stator winding
Zr = 48.; #no. of conductors in rotor winding
Rr = 0.013; #ohm/phase(ressmath.tance rotor windig)
XL = 0.048; #ohm/phase(leakega reacmath.tance)
Vs = 400.; #V
# Calculations and Results
#(a)
Eo = Vs*Zr/Zs; #V(rotor emf)
print "(a) Rotor emf(V) : %.2f"%Eo
#(b)
S = 4./100; #slip
Eo = Eo*S; #V(rotor emf for 4% slip)
print "(b) Rotor emf at 4%% slip(V) : %.2f"%Eo
Z = math.sqrt(Rr**2+(S*XL)**2); #ohm/phase(rotor impedence at 4% slip)
Ir = Eo/Z; #A(Rotor curren at 4% slip)
print "(b) Rotor curren at 4%% slip(A) : %.2f"%Ir
#(c)
fi_r = math.degrees(math.atan(S*XL/Rr)); #degree
print "(c) Phase difference at 4%% slip(degree) : %.2f"%fi_r
S = 100./100; #100% slip
fi_r = math.degrees(math.atan(S*XL/Rr)); #degree
print "(c) Phase difference at 100%% slip(degree) : %.2f"%fi_r
# note : rounding off error.