Measure the atmospheric pressure value with Torrecholi test (vacuum is placed on the silver surface inside the glass tube). The following process will cause the measurement value to change: A. Move the test from the foot of the mountain to the top of the mountain. B. Lower the glass tube slightly. C. Tilt the glass tube slightly. D. Use a slightly thicker glass tube The atmospheric pressure is measured by the Torricelli test (vacuum is placed on the silver surface inside the glass tube). The following process will cause changes in the measured value: A. Move the test from the foot of the mountain to the top of the mountain. B. Lower the glass tube slightly. C. Tilt the glass tube slightly. D. Use a slightly thicker glass tube

Measure the atmospheric pressure value with Torrecholi test (vacuum is placed on the silver surface inside the glass tube). The following process will cause the measurement value to change: A. Move the test from the foot of the mountain to the top of the mountain. B. Lower the glass tube slightly. C. Tilt the glass tube slightly. D. Use a slightly thicker glass tube The atmospheric pressure is measured by the Torricelli test (vacuum is placed on the silver surface inside the glass tube). The following process will cause changes in the measured value: A. Move the test from the foot of the mountain to the top of the mountain. B. Lower the glass tube slightly. C. Tilt the glass tube slightly. D. Use a slightly thicker glass tube

Torricelli experiment uses the height of the liquid column to measure the atmospheric pressure, which has nothing to do with the thickness, D error, and also has nothing to do with the length of the empty pipe, that is, the pull-up or push-down pressure only changes the length of the upper vacuum, without affecting the height of the mercury column, BC error.

Torricelli test is to measure the atmospheric pressure with the height of the liquid column, which has nothing to do with the thickness, D error, and also has nothing to do with the length of the empty pipe, that is, the pull-up or push-down pressure only changes the length of the upper vacuum, without affecting the height of the mercury column, BC error.

There is a U-shaped pipe with a closed end and a uniform thickness. The upper ends of the mercury columns on both sides of the pipe are just flat. The length of the air column in the closed pipe is L1=30cm, and the atmospheric pressure is p0=75cmHg. There is a U-shaped tube with a closed end and a uniform thickness. The upper ends of the mercury columns on both sides of the tube are just flat. The length of the air column in the closed tube is L1=30cm, and the atmospheric pressure is p0=75cmHg.

Before pouring in: p1= p0, get p1=75 cmHg.
After pouring: p1 V1=p2 V2, p1/p2=L2/L1, with p2=90 cmHg.
P1=Δp + p0,Δp =15 cm Hg, i.e. the left tube is 15 cm higher than the right tube, and the right tube is 5 cm higher than the original, so the left tube is 20 cm higher than the original.
The length of mercury column is 20cm+5cm=25cm.