Chapter 1 - Introduction to electrical machines

Exa:1.9 Pg No: 39

In [2]:
N=800 #  No.of turns
Phy_1=2000*10**-6 #  Webers
Phy_2=1000*10**-6 #  Webers
t=0.1 #  seconds
e=N*(Phy_1-Phy_2)/t
print 'Emf induced in the coil = %.2f volts'%e

Emf induced in the coil = 8.00 volts

Exa:1.10 Pg No: 39

In [4]:
N=1000.0 #  No.of turns
Phy_1=2000.0*10**-6 #  Webers
#On reversal of current
Phy_2=2000.0*10**-6 #  Webers
t=0.2 #  seconds
e=N*(Phy_1-(-Phy_2))/t
print 'Average value of emf induced in the coil = %.2f volts'%e

Average value of emf induced in the coil = 20.00 volts

Exa:1.11 Pg No: 40

In [5]:
N=300 #  No.of turns
R=60 #  resitance in ohms
Phy_1=2*10**-3 #  Webers
Phy_2=3*10**-3 #  Webers
t=0.2 #  seconds
e=N*(Phy_2-Phy_1)/t
print '(1) Average emf induced in the coil = %.2f volts'%e
i=e/R
print '(2) Current through the coil = %.2f Amperes'%i

(1) Average emf induced in the coil = 1.50 volts
(2) Current through the coil = 0.02 Amperes

Exa:1.12 Pg No: 40

In [1]:
P=4 #  no of poles
N=4*250 #  No.of turns
Phy_1=40*P*10**-3 #  Webers
Phy_2=5*P*10**-3 #  Webers
t=0.1 #  seconds
e=N*(Phy_1-Phy_2)/t
print 'average value of emf induced across the feild terminals = %.2f volts'%e

average value of emf induced across the feild terminals = 1400.00 volts