22.The __ is used to decrease the voltage from 110 or 220-line voltage to 3-5 volts used by the filament circuit. a. Step-up transformer b. Step-down transformer c. High voltage circuit A B C 23. In dental radiography.the term __ is used to describe the mean energy or penetrating ability of the x-ray beam. a. Quality b. Quantity c. Intensity d. Wavelength A B C D

22. **B.** A **step-down transformer** is used to decrease voltage. A step-up transformer *increases* voltage. The high voltage circuit *is* the circuit carrying the higher voltage, not a device to change voltage.<br /><br />23. **A.** **Quality** refers to the mean energy or penetrating ability of the x-ray beam. While related, quantity refers to the *number* of x-rays produced, intensity is the number of photons per unit area per unit time, and wavelength is inversely proportional to energy (shorter wavelengths = higher energy/quality).<br />