1.

Emf and torque produced in a DC machine are proportional to ________ and _________ respectively.(a) Armature speed and armature emf(b) Armature emf and armature speed(c) Armature current and armature emf(d) Armature speed and armature currentI had been asked this question during an interview.This interesting question is from EMF and Torque Production topic in portion Circuit Model, Emf and Torque of DC Machines

Answer»

Right answer is (d) Armature SPEED and armature CURRENT

Explanation: Average coil emf GENERATED= ∅ωNP/π. Machine torque = KA*∅*Ia. Thus, average coil emf generated can also be represented as ka*∅*ω. So, average coil emf is directly PROPORTIONAL to ω (armature speed) and average torque is directly proportional to Ia (armature current).



Discussion

No Comment Found

Related InterviewSolutions