What is the best advantage achieved in exposure time, using front and back lead screens, as compared to exposure time without screens?

Related MCQs

• If an exposure time of 60 seconds and source to film distance of 365.7 m (1200 feet) is necessary for a particular exposure, what exposure time would be needed for an equivalent exposure if the source- to-film distance is changed to 457.2 m (1500 feet)?
• A radiograph is made using film X with an exposure of 10 mA-min. Film density obtained in the area of interest is 1.0. If it is desired to achieve a density of 2.0 in the area of interest, what exposure is required? (Log relative exposure = 1.1 for a density of 1.0 and 1.62 for a density of 2.0)
• A radiograph is made using film X with an exposure of 10 mA-min. Film density in the area of interest is 1.0. If it is desired to achieve a density of 2.0 in the area of interest, what exposure is required? (Log relative exposure = 1.1 for a density of 1.0 and 1.62 for a density of 2.0)
• If the required X ray exposure time for a 225 kV, 5 mA exposure is 3 minutes, approximately what exposure time would be required at 10 mA?
• If the required X ray exposure time for a 150 kV, 5 mA exposure is 2 minutes, approximately what exposure time would be required at 10 mA?
• When testing a test piece with parallel front and back surfaces, no back wall echo can be obtained. Which of the following actions might enable you to obtain a back wall echo?
• Gamma ray or high voltage X ray radiography, using film without lead screens, is likely to result in:
• Gamma ray or high voltage X ray radiography, using film without lead screens, is likely to result in:
• A good Cobalt-60 shot is made on a 7.6 cm (3 inches) steel casting using an exposure time of 10 minutes and a source-to-film distance of 91.5 (36 inches). If it is necessary to change the source-to-film distance to 61 cm (24 inches), what exposure time would produce a similar radiograph if all other conditions remain the same?
• If the required exposure time for a 2220 GBq (60 curie) Ir-192 source is 2 minutes, what exposure time would be required at 1110 GBq (30 curie) source: