Questions with Complete Solutions
Any exposed live parts must be guarded if they are operating at - Answer-50V or more
between terminals
Which of the following are most likely to use dynamic braking? - Answer-Forklifts
In a DC series motor, how much of its full-load torque is developed at starting? -
Answer-500%
For a given number of poles, which of the following determines the speed of an AC
motor? - Answer-Frequency
Which of the following motors is used where the required starting torque is high and
speed control is desirable - Answer-compound
the synchronous speed at which a four-pole, 60Hz induction motor operates is -
Answer-1,800 rpm
slip is best described as . . . - Answer-The difference between the synchronous speed
and the speed of the rotor in an induction motor
Which of the following motor operate on the principle of a rotating magnetic field? -
Answer-induction motors
horsepower is used to rate the - Answer-output capacity of a motor
How many motor designs does NEMA designate - Answer-5
In a split-phase motor, how much greater is the starting current when compared to the
full-load current? - Answer-6 to 8 times
The capacitor-start motor is the single-phase motor type that has the - Answer-highest
starting torque
The wound rotor induction motor is used - Answer-for speed control and to limit starting
current
which of the following is true of shaded-pole motor? - Answer-they have a low starting
torque, a low efficiency, and a high noise level
For a constant-torque load, the horsepower increases and decreases - Answer-in direct
proportion to the speed