北交《测试技术》在线作业一(国外英文资料).doc

北交《测试技术》在线作业一(国外英文资料) North to test technology online homework First, radio questions (10 questions, 30 points) 1., in order to detect the concentration of harmful gases around our living environment. A. humidity sensor B. temperature sensor C. gas sensor D. force sensitive sensor Correct answer: 2. ultrasonic velocity in organic glass compared to sound velocity in steel. A. Small B. C. equality Correct answer: 3. the angle theta in EH=KHIBcos theta refers to. A. the angle between the line of force and the plane of the Holzer plane B. the angle between the line of force and the direction of the current within the Holzer element C. the angle between the line of force and the perpendicular line of the Holzer sheet Correct answer: The greater the value of 4. (), the greater the thermoelectric power of the thermocouple output. A. hot end diameter B. hot end and cold end temperature The temperature difference between the hot and cold ends of C. Conductivity of D. thermoelectric pole Correct answer: When the base input of the 5. OC gate is low and the collector is not connected to the pull resistor, the output of the collector is (). A. high level B. low level C. high impedance state D. earth to earth conduction Correct answer: 6., the Holzer component uses constant current source excitation to (). A. improves sensitivity B. overcome Wen Piao C. reduces the equipotential potential Correct answer: 7., in the workshop, with the microcomputer digital thermometer to measure the temperature of the furnace, should be used () more appropriate. A. calculation correction method Mechanical zero adjustment method of B. instrument C. ice bath D. bridge compensation method Correct answer: 8. ultrasonic wave frequency of ultrasonic sensors. A. is below 16Hz B. is below 10kHz C. is higher than 10kHz D. is higher than 20kHz Correct answer: The 9. semiconductor sheet is placed in a magnetic field, and when an electric current flows through it, an electromotive force is generated in the di