DC generator questions

[liamhutch]

Hello, this is my first post and hope to contribute in the future, however I am struggling right now with some questions and would be very grateful if someone could help me, thank you.

a) a DC generator has a machine constant k=0.075 volts/rpm, the armature resistance RA=0.2 ohms, the generator is connected to a load resistance = 2.56 ohms and supplies the load with a current 41 Amps

calculate
i) the generator output voltage V

ii) the internal induced voltage E

iii) the electrical output power

iv) the mechanical input power

v) the internal power loss

vi) the generator turning speed

 

[mister_rf]

DC generator has a machine constant k=0.075 volts/rpm,
the armature resistance RA=0.2 ohms,
the generator is connected to a load resistance = 2.56 ohms
supplies the load with a current 41 Amps

r=0.2 ohms
R= 2.56 ohms
I= 41 Amps


i) the generator output voltage U
U= RI = 2.56 *41= 104.96V

ii) the internal induced voltage E
E= I (R +r) = 41 (2.56 + 0.2 ) = 113.16V

iii) the electrical output power
P= UI = 104.96*41= 4303.36W

iv) the mechanical input power
If efficiency 100% > Pm = E I = 113.16 *41 = 4639.56W

v) the internal power loss
Pi = (E – U) I = (113.16 – 104.96) 41 = 336.2W

vi) the generator turning speed
E/k= 113.16/0.075 = 1508.8 rpm