Question

What is the output equation of DC machine?

(a) Output power = Output Coefficient of the machine* Diameter^2 * Length * Speed in rpm

(b) Output power = Output Coefficient of the machine* Diameter^2 * Length * Speed in rps

(c) Output power = Output Coefficient of the machine* Diameter^2 * Length / Speed in rps

(d) Output power = Output Coefficient of the machine* Diameter^2 * Length / Speed in rpm

This question was addressed to me during an internship interview.

My enquiry is from Design of Output Equations in portion Thermal Design Aspects of Electrical Machines & D.C of Design of Electrical Machines

Answer 1

The correct choice is (b) Output power = Output Coefficient of the machine* Diameter^2 * Length * Speed in rps

Explanation: While calculating the output power of the DC machine, the coefficient of output equation, the diameter of the conductor, the length of the conductor and the speed is required. Speed should be in rotations per second only.