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A separately excited DC motor has the following parameters: field resistance = 250 ?, armature resistance...

A separately excited DC motor has the following parameters: field resistance = 250 ?, armature resistance = 0.03 ?, terminal voltage = 250 V and field voltage = 250 V. Initially the machine runs at 1000 rpm with the terminal voltage = 250 V and armature current = 120 A. a) find the speed of the motor if the load torque dropped to 50% of its original value, b) find the speed of the motor if the armature voltage is reduced to 200 V. c) find the speed of the motor if the field voltage is reduced by 10 %. d) find the speed of the motor if the field voltage is reduced by 95%.

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