Electrical Machines Questions and Answers – DC Motors
Operating Characteristics of DC Motors
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It is advised not to run dc series motor with no load. Why?
Correct!
Wrong!

The torque vs armature current of a differential compound motor in the strong field is
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It is impossible to start a differential compounded dc motor.
Correct!
Wrong!

How will the speed torque characteristic of a dc shunt motor and cumulatively compound dc motor perform at no load?
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Identify the speed torque characteristics of a dc series motor.
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The speed torque of the differential compound dc motor is shown below. What conclusions can be made?
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For a dc shunt motor of 5 kW, running at 1000 rpm, the induced torque will be
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A student is given a differential compound motor and he has been asked to make it start. How will he try?
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Mark the correct option which affects the terminal voltage of a dc shunt motor.
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The flux and the internally generated voltage of a dc machine is a ________ function of its magnetomotive force.
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A dc shunt motor is connected to the source through 3point starter. Suddenly if we starter handle is moved fastly from off to on position, then
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Choose the best option which identifies about the below characteristics.
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The speed torque characteristics of the dc motor is best described by following the equation
w=(Vt/k*flux)Ra*T/((R*flux)^2)
w=(Vt/k*flux)Ra*T/((R*flux)^2)
Correct!
Wrong!

The torque characteristic is best described for a dc series motor with respect to armature current is
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For a 100 hp 250 V, compound dc motor with compensating winding has a field current of 5 A to produce a voltage of 250 V at 1200 rpm. What will be the shunt field current of this machine at no load?
Correct!
Wrong!
