Question

Define critical speed and critical resistance of a dc generator

Answer 1

Answer:Critical Field Resistance: It is that value of the field resistance at which the D.C. shunt generator will fail to excite. Critical Speed: It is that speed for which the given shunt field resistance becomes the critical field resistance.

Explanation:

Answer 2

Answer:

 Critical speed:

The critical speed of the DC generator is the maximum speed above the DC generator, where it cause damage or failing of the circuit.

The critical speed is the maximum resistance of the circuit in which the shunt generator resistance become the critical field and produce the voltage when the critical filed of the resistance is high as compared to the field circuit resistance.  

Critical resistance:

 The critical resistance of the Dc generator is associated with the shunt DC generator. In which the shunt generator get excited and produce the induced voltage across the generator armature as the voltage is directly proportional to the DC generator flux.