57. Regarding secondary barriers, which of the following 15 not true ?
(A) secondary barriers provide protection from stray radiation
(8) no secondary barrier is required for areas protected by primary barrier
(€) kVp and patient thickness plays a role in determining secondary barriers requirements
(12) regarding inverse square attenuation of scattered radiation, the distance is measured from
the centre of the patient
58. Regarding leakage radiation, which of the following is not true ?
(^) maximum permissible leakage exposure 1 meter from a diagnostic X-ray tube is
0.5 R/hour
(B) leakage radiation is the radiation that passes through the lead shielding in the tube housing
when the beam ig turned on
(5) leakage radiation will occur even if the collimator shutter is completely closed
(D) Half value method is useful to reduce leakage radiation to permissible levels
59. Regarding Intensifying screens, which of the following is not true ?
(^) reflecting coat is made up of titanium dioxide
(B) light produced by calcium tungstate crystal is seen by the eyes as violet colour
(C) thick phosher will result in slow speed
(0) high speed means less detail of film
60. Regarding Computerized Radiography, which of the following is not true ?
(A) the latent image will be readable വി up to 1 hour
(8) ‏ومع‎ a photo stimulable Phosphor as image receptor
(€) commonly used Phosphar is enropium activated barium flurobromide
(D) CR plate is scanned with light from thallium neon laser
61. Regarding Developing agents ingredients, which of the following is not true ?
(A) அயர (8) hardening agent (C) preservative (D) antifogants
62. Regarding movement of grids, which of the following is not true ?
(A) invented by Hollis's E Potter in 1921
(0) will decrease the patient radiation dose
(C) are reciprocating
(D) will move a little time more than the exposure time to avoid grid lines
68. Regarding Air gap technique, which of the following is not true ?
(A) प्रा chest radiography FFD is increased to 8 feet
(8) an alternative method to reduce scater radiation
(9 1%tinch of air gap improves contrast more than any subsequent inches
(12) used in 2 clinical situations, chest radiography and magnification radiography
64, Regarding Superconducting magnets, which of the following is not true ?
(ക) take advantage of zero resistance that certain materials at very low temperatures
(8) the power supply must be maintained throughout
(9) entire magnetic system must be at about 4 degree K
(D) low temperature is maintained with liquid helium
65, Regarding Superconducting magnets, which of the following is not true 7
(ക) Quenching result in 1055 of magnetization and liquid helium
(8) high field strength is main advantage
(C) rapid quenching results in release of large amounts of nitrogen
(D) main disadvantage is the high cost
153/2014 10 A