Electrical - Motors Test Part 2

Electrical - Motors Test Part 2 The synchronous speed at which a four-pole. 60Hz induction motor operates is _________ rpm. a. 6,900 b. 2,500 c. 1,140 d. 1,800 - 1,800 The most common service factor appearing on a motor's nameplate is: a. 115 b. 1.15 c. 2 d. 1.5 - 1.15 The _______represent(s) the stationary magnet of a DC motor. a. armature b. rotor c. commutator d. field poles - field poles The _______ DC motor is used where the required starting torque is high and speed control is desirable. a. compound b. series C. brushless d. shunt - compound Of the following motors, a _______ motor is the best installation choice for an application requiring adjustable speeds. a. DC b. capacitor-start c. synchronous d. split-phase - DC A ________ motor provides constant speed from no-load conditions to full-load conditions. a. series DC b. squirrel cage induction e. shunt DC d. synchronous - synchronous Motor circuits are covered in a. NEC Article 500 b, NEC Article 250 c. NEC Article 430 d. NEC Article 300 - NEC Article 430 Any exposed live parts operating at or more than ______ between terminals must be guarded a. 240V b. 50V C. 15V d. 600V - 50V The value indicated in rpm on the nameplate is the _________. a. duty rating b. rated full-load speed c. power factor d. rated horsepower - rated full-load speed The two ways of varying the speed on a DC shunt motor is to adjust the voltage and current on the field winding or the __________. a. armature b. stator c. rheostat d. controller - armature For a constant-torque load the horsepower