When other operating conditions are held constant, a change in tube current causes a change in radiation intensity emitted from an X-ray tube, the intensity being approximately proportional to tube current. What is the primary factor that prevents this from being exactly proportional?

Which of the following is not a factor in determining subject contrast?

The degree of concentration of the radioactive material in a gamma ray source referred to as the:

A curve that relates density with the logarithm of exposure or of relative exposure is called:

In million-volt radiography, filtration at the tube:

Co-59 becomes Co-60 when it is placed in a nuclear reactor where it captures:

For a given change in the radiation exposure, film contrast is the inherent ability to show:

The “photoelectric” effect involves:

The developer solution is:

A general rule governing the application of the geometric principles of shadow formation states that the:

When electrons of many different energies strike a target, a continuous spectrum of X-rays is generated. These X-rays are known as:

All other factors being the same, radiographic sharpness or definition is improved by using:

The minimum source-to-film distance needed to produce acceptable radiographs depends on the focal spot (source) size, the maximum allowable unsharpness, and the:

The major advantages of automatic film processing are:

Which of the following should be done to preserve radiographs during long-term storage?

The difference in density between different parts of a radiograph is called:

In radiography the term “RBE” stands for:

A given radiation dose will cause less damage if it is received over a very short period of time than if it is received over a long period of time.

The earliest indications of radiation damage may be detected in the:

The formula for the inverse square law is:

The intensity of the light emitted by the fluorescent screen depends upon the intensity of the:

The measure of the accuracy of the radiograph as a nondestructive testing tool is called the _____________ of the radiograph.

A gas-filled region located in an electrical field created by electrodes across which a potential difference is applied forms the major portion of:

Two serious obstacles to high-intensify fluoroscopy are:

. In general, the quality of fluoroscopic equipment is best determined:

. In fluoroscopic testing, a fundamental difficulty is the relative low brightness level of the images. One method for increasing brightness utilizes one of the following which converts light energy from the initial phosphor surface to electrons which are accelerated and focused onto a smaller fluorescent screen.

The absorption of radiation by a material varies:

In the microradiographic technique:

For practical purposes, the shape of the characteristic curve of an X-ray film is:

The term which describes the total absorption of the useful beam caused by the X-ray tube wall, the wall of the tube housing, and any material between the tube and housing is:

The fact that gases, when bombarded by radiation, ionize and become electrical conductors make them useful in:

The velocity of electrons striking the target in an X-ray tube is a function of the:

The uneven distribution of developed grains within the emulsion of a processed X-ray film causes the subjective impression of:

 The specific activity of an isotopic source is usually measured in:

Which of the following isotopes has the longest half-life?

The primary form of energy conversion when electrons strike a target in an X-ray tube results in the production of:

Almost all gamma radiography is performed with:

The amount of unsharpness or blurring of a radiograph is:

Images of discontinuities close to the source side of the specimen become less clearly defined as:

The inherent filtration of an X-ray tube is a function of the: