Two DC shunt machines, Machine A and Machine B when tested by Hopkinson's method, gave the...

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Two DC shunt machines, Machine A and Machine B when tested by Hopkinson's method, gave the following data: Line voltage 280 V; line current excluding both the field currents is 60 A; Machine B armature current is 280 A. Field currents of machine A and machine B are 7 A and 5 A respectively. The armature resistance of machine A and machine B is 0.025 Ohm and 0.025 Ohm respectively. The brush drop is 1.5 V for each of the machines. (i) Which machine is working as motor and which machine is working as generator. Choose the correct option from below: Option-1: Machine B -Motor & Machine A -Generator; Option-2: Machine A -Motor & Machine B-Generator; [1] (ii) Determine the rotational loss (P_rotational, kW) of each machine. Assume the rotational loss of each machine is equal to each other. [2] (iii) Total losses (P_loss_gen, kW) of the machine working as generator. (iv) Total losses (P_loss_mot, kW) of the machine working as motor. (v) Efficiency (Eff_gen, %) of the machine working as generator. (vi) Efficiency (Eff_mot, %) of the machine working as motor. [2] [2] [2] [2] Two DC shunt machines, Machine A and Machine B when tested by Hopkinson's method, gave the following data: Line voltage 280 V; line current excluding both the field currents is 60 A; Machine B armature current is 280 A. Field currents of machine A and machine B are 7 A and 5 A respectively. The armature resistance of machine A and machine B is 0.025 Ohm and 0.025 Ohm respectively. The brush drop is 1.5 V for each of the machines. (i) Which machine is working as motor and which machine is working as generator. Choose the correct option from below: Option-1: Machine B -Motor & Machine A -Generator; Option-2: Machine A -Motor & Machine B-Generator; [1] (ii) Determine the rotational loss (P_rotational, kW) of each machine. Assume the rotational loss of each machine is equal to each other. [2] (iii) Total losses (P_loss_gen, kW) of the machine working as generator. (iv) Total losses (P_loss_mot, kW) of the machine working as motor. (v) Efficiency (Eff_gen, %) of the machine working as generator. (vi) Efficiency (Eff_mot, %) of the machine working as motor. [2] [2] [2] [2]

Answer rating: 100% (QA)

i Which machine is working as motor and which machine is generator Based on the given information Machine A is working as the motor and Machine B is working as the generator Heres the reasoning In Hop... View the full answer