A dc motor with its rotor and field coils connected in series has an internalresistance of 2.00 Ω. When running at full load on a 120 V line, itdraws a 4.00 A current. What is the mechanical power developed?
A dc motor with its rotor and field coils connected in series has an internal
resistance of 2.00 Ω. When running at full load on a 120 V line, it
draws a 4.00 A current. What is the mechanical power developed?
The emf equation of a motor is given by the equation,
where V is the voltage, I is the current, R is the resistance and Eb is the emf.
Mechanical power is the rate at which the work can be done. It can be determined by the equation,
where Eb and I is the emf and current.
Given:
The emf in the rotor can be determined by re-arranging equation (1).
Substitute the given values in the above equation to find the emf in the rotor.
Now, calculate the mechanical power developed using equation (2).
Substitute all the given and calculates values in equation (2).
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