【Experiment】. 1.Use Wheatstone bridge to measure the resistance of the resistors 1)According to Figure 1,take the bridge measuring device; 2)Choose the appropriate ratio of R1/R2 to ensure that significant digits of the measured resistance: 3)Calculate the relative uncertainty of the measured resistance 2.Use four-probe method to measure low resistance. 1)According to Figure 5,set up the instrument. 2)Change the output current,measure the resistance of the S-1,S-2 and S-3,each measurement should have 15 data points at least. 3)Change the contact resistance and the wire resistance to check their influence on the measurement.Write down your method and conclusion. 4)Calculate the resistivity. 待测电阻 V Figure 5 Circuit diagram of the four-probe method 3.Use non-balanced bridge to complete the following task: 1)Design a thermistor thermometer,measuring range 0~100C,Output voltage:0~100 mV 2)Design a Pt100 resistor thermometer,measuring range 0~100C,Output voltage:0~50 mV,maximal error under 0.5 C. 【Attention】 1.Check the circuit carefully,make the circuit firm and orderly. 2.Be careful with the boiling water. 3.The designed parameters should match the practical parameters of the elements. 【Question】 1.What is balanced bridge?What is non-balanced bridge? 2.What is comparative method?Which quantities to be compared in the Bridge measurement method? 3.What is the bridge to reach balance?How to determine the bridge to reach balance in the 55 【Experiment】 1. Use Wheatstone bridge to measure the resistance of the resistors 1) According to Figure 1, take the bridge measuring device; 2) Choose the appropriate ratio of R1/R2 to ensure that significant digits of the measured resistance; 3) Calculate the relative uncertainty of the measured resistance. 2. Use four-probe method to measure low resistance. 1) According to Figure 5, set up the instrument. 2) Change the output current, measure the resistance of the S-1, S-2 and S-3, each measurement should have 15 data points at least. 3) Change the contact resistance and the wire resistance to check their influence on the measurement. Write down your method and conclusion. 4) Calculate the resistivity. Figure 5 Circuit diagram of the four-probe method 3. Use non-balanced bridge to complete the following task: 1) Design a thermistor thermometer, measuring range 0～100℃,Output voltage:0～100 mV 2) Design a Pt100 resistor thermometer, measuring range 0～100℃,Output voltage:0～50 mV, maximal error under 0.5 ℃. 【Attention】 1．Check the circuit carefully, make the circuit firm and orderly. 2．Be careful with the boiling water. 3．The designed parameters should match the practical parameters of the elements. 【Question】 1． What is balanced bridge? What is non-balanced bridge? 2． What is comparative method? Which quantities to be compared in the Bridge measurement method? 3． What is the bridge to reach balance? How to determine the bridge to reach balance in the