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University experiment on the characteristics of thermistor
(1) Adjust the ratio of ohmmeter, and carry out ohm zero adjustment after changing the ratio every time.

(2) According to the experimental data in the table, draw corresponding points in the coordinate system, and then make an image, as shown in the figure.

(3) According to the R-t image of thermistor, the resistance of thermistor decreases with the increase of temperature.

(4) According to the R-t image, when the temperature is 15℃, the resistance of the thermistor is 40Ω, and the internal resistance of the ammeter is Rg = UI-R = 8v0.01-400 = 400Ω.

When the circuit current is 14mA=0.0 14A, the thermistor resistance value r = UI-rg = 80.014-400 ≈171ω, and the display temperature is 34℃.

(5)A, thermal bimetal sensor and reed switch are equivalent to switches in the circuit, which can control the on-off of the circuit, so A is correct;

B, the main component of the electronic scale is the pressure sensor, and the electronic scale converts force into voltage, so B is correct;

C, photoelectric mouse device and fire alarm application is photosensitive sensor, so c is correct;

D, microphone is a commonly used acoustic sensor, its function is to convert acoustic signals into electrical signals, so D is wrong; So choose ABC ..

So the answer is: (1) Ohm returns to zero; (2) As shown in the figure; (3) The resistance of thermistor decreases with the increase of temperature; (4)34℃; (5) Activity-based costing.