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Short shunt compound generator emf, 80 A at 220 V

Short answer

Shunt field voltage is V + I_L R_se = 220 + 80×0.05 = 224 V. Shunt current 224/100 = 2.24 A, armature current 80 + 2.24 = 82.24 A. Generated emf E = 224 + 82.24×0.1 = 232.22 V.

A short shunt compound generator delivers a current of 80 A to the load at 220 V. The shunt field, series and armature winding resistances are 100 Ω100\ \Omega, 0.05 Ω0.05\ \Omega and 0.1 Ω0.1\ \Omega respectively. Calculate the emf generated by the armature.

In a short shunt compound generator the shunt field is connected across the armature only, so the series field carries the load current ILI_L and the shunt field sees V+ILRseV + I_LR_{se}.

Given: IL=80I_L = 80 A, V=220V = 220 V, Rsh=100 ΩR_{sh} = 100\ \Omega, Rse=0.05 ΩR_{se} = 0.05\ \Omega, Ra=0.1 ΩR_a = 0.1\ \Omega.

       Ia                 Rse   IL
  +--->---+----------+--[~~~]--->--+--o +
  |       |          |            |
 (E,Ra)   |        [Rsh]        Load
  |       |          |            |
  +-------+----------+------------+--o -

Step 1: Voltage across the shunt field

Vsh=V+ILRse=220+80(0.05)=224.00 VV_{sh} = V + I_LR_{se} = 220 + 80(0.05) = 224.00\ \text{V}

Step 2: Currents

Ish=VshRsh=224.00100=2.240 A,Ia=IL+Ish=80+2.240=82.240 AI_{sh} = \frac{V_{sh}}{R_{sh}} = \frac{224.00}{100} = 2.240\ \text{A}, \qquad I_a = I_L + I_{sh} = 80 + 2.240 = 82.240\ \text{A}

Step 3: Generated emf

E=Vsh+IaRa=224.00+(82.240)(0.1)=232.22 VE = V_{sh} + I_aR_a = 224.00 + (82.240)(0.1) = 232.22\ \text{V}

Answer: generated emf E=232.22 VE = 232.22\ \text{V}.

✓ Answer checked by Claude Opus 5.5 (high effort)

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