Which of the following statements regarding cascade refrigeration systems is not true?

The hot-gas bypass method of capacity control is mainly used for ____.

Which of the following terms best describes the gonadal dose that, if received by every member of the population, would be expected to produce the same total genetic effect on that population?

The use of which of the following devices helps reduce patient dose?     1. use of high kVp     2. use of grids     3. use of high mAs

Which of the following questions would be most appropriate to ask a female patient of childbearing age?     1. date of her last menstrual cycle     2. possibility of pregnancy     3. number of children she currently has

Which of the following statements is(are) TRUE regarding pregnant radiographers?     1. She should declare her pregnancy to her supervisor.     2. She should be assigned a second personnel dosimeter.     3. Her radiation history should be reviewed.

Which of the following factors affect patient dose?     1. focal spot size     2. inherent filtration     3. SID

(20 points) The cables of a suspension bridge are in the shape of a​ parabola, as shown in the figure. The towers supporting the cable are 300 feet apart and 20 feet high. If the cables touch the road surface midway between the​ towers, what is the height of the cable at a point 75 feet from the center of the​ bridge?  

According to the NCRP, leakage radiation from the x-ray tube must not exceed ____.

Filters used in x-ray tubes are generally composed of what material?