Question
A DC shunt motor draws 13 amperes from a 250 volt supply. The armature resistance is 0,3 ohms and the field resistance is 120 ohms. Calculate the efficiency of the motor
Answers
Answered by
GPT 3.5
To calculate the efficiency of the DC shunt motor, we first need to calculate the input power and the output power.
Input power (Pin) = VI
Pin = 250V * 13A
Pin = 3250 W
Output power (Pout) = V * I - I^2 * Ra
Pout = 250V * 13A - (13A)^2 * 0.3 ohms
Pout = 3250W - 42.9W
Pout = 3207.1W
Efficiency = (Output power/Input power) * 100%
Efficiency = (3207.1W / 3250W) * 100%
Efficiency ≈ 98.69%
Therefore, the efficiency of the motor is approximately 98.69%.
Input power (Pin) = VI
Pin = 250V * 13A
Pin = 3250 W
Output power (Pout) = V * I - I^2 * Ra
Pout = 250V * 13A - (13A)^2 * 0.3 ohms
Pout = 3250W - 42.9W
Pout = 3207.1W
Efficiency = (Output power/Input power) * 100%
Efficiency = (3207.1W / 3250W) * 100%
Efficiency ≈ 98.69%
Therefore, the efficiency of the motor is approximately 98.69%.