The motor-field rheostat should be ___

The motor-field rheostat should be ____ when...

Question 1 / 27070JbAB26yNfJ9odSgcPsYl

Question 1 of 27070JbAB26yNfJ9odSgcPsYl

The motor-field rheostat should be ____ when starting a DC motor generator set:

Question 1 of 27070

The motor-field rheostat should be ____ when starting a DC motor generator set:

🔍 Key Concepts

• Behavior of a DC motor when field strength is high vs low at start • Relationship between back EMF (counter-voltage) and speed in a DC motor • Purpose of using a rheostat in the field circuit during starting

💭 Think About

• Think about what happens to starting current and torque if the field is made very weak versus very strong at the instant of starting • Ask yourself: Is it safer for the machine and supply to start with strong field (high flux) or weak field (low flux)? Why? • Consider which setting of the field rheostat (minimum or maximum resistance) produces the strongest magnetic field in the motor at start

✅ Before You Answer

• Recall that field current increases when field resistance decreases, and decreases when field resistance increases • Verify which condition (strong or weak field) gives better control of starting current and torque in a DC motor • Confirm that the question is asking about the motor-field rheostat, not the armature rheostat, and match that to the correct choice description

Question 1 of 27070

The motor-field rheostat should be ____ when starting a DC motor generator set:

Minimum resistance in the armature circuit

Minimum resistance in the field circuit

Maximum resistance in the field circuit

None of the above

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