Find the total emf generated in a shunt generator which delivers 200 A at terminal voltage of 230 V, the armature resistance and shunt field resistance are 0.08 Ω and 50 Ω respectively.

Find the total emf generated in a shunt generator which delivers 200 A at terminal voltage of 230 V, the armature resistance and shunt field resistance are 0.08 Ω and 50 Ω respectively. Correct Answer 246.4 V 

Circuit of DC shunt generator as follows:

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• The terminal voltage of the dc shunt generator on loading decrease slightly
• We know that EMF generate (E) in a D.C generator is the sum of terminal voltage (V) and the voltage drop in the armature winding due to the current flowing through it
• V = E – Ia × Ra
• When the generator is loaded the current flowing through the armature increases to generate the required torque to rotate the load
• This increased current causes the drop in terminal voltage of the generator

Calculation:

We have,

I_L = 200 A

V_t = 230 volts

R_a = 0.08 Ω and,

Rsh = 50 Ω

In shunt generator,

I_a = I_sh + I_L

And, I_L = V_t/R_sh = 230/50 = 4.6 A

Hence,

I_a = 200 + 4.6 = 204.6 A

Now,

E = V_t + I_aR_a = 230 + (204.6 × 0.08) = 246.4 V