中级电工考试(国外英文资料).doc

中级电工考试(国外英文资料) The total current of parallel circuit is equal to the resistance (and current) The number of 3 lines per unit area vertically through the called (magnetic induction) 4 when wt=240 degrees, I1 I2 I3 (negative positive.0 respectively.) 5Y D refers to the step-down start when the motor is started, the stator winding connection to form Y, (decrease) starting voltage limit current Ecological damage does not belong to the following 6 forms of pollution in the (subsidence) 7 the following is not a natural electromagnetic pollution is (RF electromagnetic pollution) 8 noise can be divided into aerodynamic noise (mechanical noise and electromagnetic noise) 9 electrical instrumentation instructions according to the mechanism and working principle. (magnetoelectric meter and electric meter) 10 the following electrical indicating instrument in measuring instrument according to the object (power and phase meter) 11 in the process of using electrical indicating instrument. The accuracy is one of the most important technical parameters, the accuracy is usually divided into grade (grade seven) 12 in order to improve the measurement accuracy, in the selection of instruments, as far as possible to make measurements in full scale value meter (2 / 3) 13 electrical indicating instrument in use, usually depends on the accuracy of the instrument, such as (2.5) instruments commonly used in engineering measurement The frequency range of 14 electronic measurement is extremely wide, its low frequency has entered the 10 - 4, 10 - 5 HZ range, while the high-end has reached (4 x 10 - 10) 15 universal milling machine worktable about motion control by the control handle, the linkage control switch SQ1 and SQ2, which respectively control the work table (right and left) 16X6132 type universal milling machine spindle stop, press the stop button SB11 or SB21, cut off the power supply circuit contactor KM1 coil, and connect the spindle brake electromagnetic clutch (YC1), the spindle can s