Electrical Machines
Consider the following statements: To control the speed of a dc shunt motor above the base speed over a reasonably wide range, the motor must 1. have compensating winding 2. have interpole winding 3. be started using a 3-point starter 4. be started using a 4-point starter Of these statements

 1, 2 and 3 are correct
 1 and 3 are correct
 1, 2 and 4 are correct
 2 and 4 are correct

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Electrical Machines
A dc shunt generator, when driven without any excitation, showed an open circuit voltage of 12 V. When the field winding was excited, the voltage dropped to zero. It happened because

 there was a break in the armature circuit
 there was no residual magnetism in the field circuit
 field winding was wrongly connected
 field resistance was higher than critical resistance

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