Question 136Electricity & Electronics - 1st Asst/Chief

The correct answer is D) With a constant DC generator armature RPM at rated speed and the DC generator field current at maximum, the DC winch motor speed increases with decreased DC motor field current from maximum to minimum. This is correct because in a Ward-Leonard drive system, the speed of the DC winch motor is controlled by adjusting the DC motor field current. With a constant generator armature speed and maximum generator field current, decreasing the DC motor field current will increase the motor speed, allowing the winch to accelerate from base speed to maximum speed at constant horsepower. The other options are incorrect because they describe the opposite relationship between motor field current and speed, which is not consistent with the operating principles of a Ward-Leonard drive.