RT level I

Question 1

Although there may be other reasons for using calcium tungstate screens in industrial radiography,
they are most often used to:

Answer 1

Decrease exposure time.

Question 2

An excellent radiograph is obtained under given conditions of exposure with the film located at a distance of 36 in. (914.4 mm) from the target of the X-ray tube. If the film is now placed only 18 in. (457.2 mm) from the target, and all exposure conditions except time are held constant, the new exposure time will be:

Answer 2

Only about 25% as long as the original exposure
time.

Question 3

An excellent radiograph is obtained under given exposure conditions with a tube current of 5 mA and an exposure time of 12 min. If other conditions are not changed, what exposure time would be required if the X-ray tube current could be raised to 10 mA?

Answer 3

6 min.

Question 4

In film radiography, image quality indicators (IQls) are usually placed:

Answer 4

On the source side of the test object.

Question 5

When radiographing to the 2-2T quality level, and ASTM IQI for 0.5 in. (12.7 mm) thick 2024 aluminum alloy has the thickness of:

Answer 5

0.010 in (0.254 mm)

Question 6

The penetrating ability of an X-ray beam is governed by:

Answer 6

Kilovoltage.

Question 7

Co-60 used in nondestructive testing emits:

Answer 7

Gamma rays.

Question 8

A densitometer is an instrument for measuring:

Answer 8

Film density.

Question 9

Three liquids which are essential to process an exposed film properly are:

Answer 9

Developer, fixer, and water.

Question 10

The two most common causes for excessively high-density radiographs are:

Answer 10

Overexposure and overdevelopment.