Electrical Machines
DC Machines
Starting, Braking and Testing of DC Motor
Questions mapped to Starting, Braking and Testing of DC Motor under DC Machines.
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IncorrectA 4-point starter is used to start and control the speed of a
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Sign in to UnlockA 240V, dc shunt motor draws 15A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5Ω and the field winding resistance is 80Ω.
The net voltage across the armature resistance at the time of plugging will be
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Sign in to UnlockA 240V, dc shunt motor draws 15A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5Ω and the field winding resistance is 80Ω.
The external resistance to be added in the armature circuit to limit the armature current to 125% of its rated value is
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Sign in to UnlockTo conduct load test on a dc shunt motor, it is coupled to a generator which is identical to the motor. The field of the generator is also connected to the same supply source as the motor. The armature of the generator is connected to a load resistance. The armature resistance is 0.02 p.u. armature reaction and mechanical losses can be neglected. With rated voltage across the motor, the load resistance across the generator is adjusted to obtain rated armature current in both motor and generator. The p.u. value of this load resistance is
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