RA 202 Physics Class 2

Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.

____	1.	A slit camera is used to measure
1. focal spot size
2. intensifying screen resolution
3. SID resolution
a.	1 only	c.	1 and 3	
b.	1 and 2	d.	1, 2 and 3	

____	2.	What type of switch must be utilized for the exposure button on the control panel?
a.	simple switch	c.	dead-man switch	
b.	rheostat	d.	none of these	

____	3.	How many pulses per cycle exist in a three phase, six pulse generator?
a.	3	
b.	6	
c.	120	
d.	360	
e.	720	

____	4.	How many pulses per second exist in a three phase, twelve pulse generator?
a.	6	c.	360	
b.	12	d.	720	

____	5.	A spinning top device can be used to evaluate
1. timer accuracy
2. rectifier failure
3. the effect of kVp on contrast
a.	1 only	c.	1 and 2	
b.	2 only	d.	1, 2 and 3 	

____	6.	The input phosphor of the image intensifier is responsible for converting _____ to _____.
a.	x-rays to electrons	c.	electrons to visible light	
b.	x-rays to visible light	d.	visible light to electrons	

____	7.	The component of the image intensifier which accelerates and focuses electrons toward the output phosphor is the
a.	photocathode	c.	input phosphor	
b.	electrostatic lenses	d.	focal point	

____	8.	If the input phosphor receives 100 x-ray photons and the output phosphor receives 500,000 light photons, what is the flux gain?
a.	50	c.	5,000	
b.	500	d.	50,000	

____	9.	When switching from a 12 inch diameter input phosphor to a 6 inch diameter, what is the minification gain?
a.	2	c.	4	
b.	3	d.	6	

____	10.	What would the brightness gain be with a minification gain of 3 and a flux gain of 3,000?
a.	1,000	c.	6,000	
b.	3,000	d.	9,000	

____	11.	What is the magnification factor when going from a 27cm input phosphor size to a 17cm input phosphor size?
a.	1.2	c.	2.1	
b.	1.5	d.	3.3	

____	12.	What type of x-ray tube support system allows movement anywhere in the room both longitudinally and transversely?
a.	floor mounted tube	c.	upright unit	
b.	floor to ceiling mounted tube	d.	ceiling mounted tube	

____	13.	What type of tube support is utilized during mobile fluoroscopy?
a.	mobile floor mount	c.	c-arm	
b.	overhead tube 	d.	head unit	

____	14.	Each cell of the image matrix is called a:
a.	row 	c.	pixel	
b.	colum	d.	square	

____	15.	Which device utilized during fluoroscopy compensates for differences in tissue thickness by adjusting kVp or mA automatically?
a.	ABC	c.	R and F	
b.	AEC	d.	FFD	

____	16.	In which of the following imaging systems will there be no latent image?
a.	CR	c.	DR	
b.	conventional film	d.	all have latent images	

____	17.	Which type of unit would allow MeV to be utilized?
a.	panorex	c.	c-arm	
b.	mammographic	d.	theraputic	

____	18.	Which of the following would not be considered a dedicated radiographic unit?
a.	panorex	c.	C-arm	
b.	mammography	d.	bone densitometry	

____	19.	How often should lead aprons be tested fluoroscopically for cracks?
a.	daily	c.	monthly	
b.	weekly	d.	annually	

____	20.	Which of the following interactions results in an “annhialation reaction?”
a.	photodisintegration	
b.	compton effect	
c.	pair production	
d.	Thompson scatter	
e.	characteristic radiation	

____	21.	What is responsible for the audible noise during acceleration of the anode?
a.	the bearings inside the rotor	c.	induction motor	
b.	thermionic emission	d.	tungsten vaporization	

____	22.	What is the only portion of the x-ray tube assembly located outside the glass envelope?
a.	rotor	c.	focusing cup	
b.	stator	d.	filament	

____	23.	As kV increases, wavelength _____.
a.	increases	c.	stays the same	
b.	decreases	

____	24.	How many heat units are produced from an exposure of 300mA, .2 sec, 70 kV on a three phase 12 pulse machine?
a.	4,200	c.	6,090	
b.	5,670	d.	5,922	

____	25.	If a circuit has a resistance of 24.4 ohms and is supplied with 140 V, what is the current?
a.	5.7 Amps	c.	3,416 Amps	
b.	0.17 Amps	d.	3.5 Amps	

____	26.	Which type of dedicated radiography unit orbits around the part being radiographed?
a.	panorex	c.	dedicated chest unit	
b.	bone densitometry	d.	mammographic unit	

____	27.	If a transformer has 200 V on the primary coil and 200 turns of wire, what will the voltage be on the secondary coil that possesses 40,000 turns of wire?
a.	400	c.	400,000	
b.	40,000	d.	40	

____	28.	The x-ray intensity at 40” is 200mR.  What would the intensity be at 80”?
a.	35 mR	
b.	45 mR	
c.	50 mR	
d.	60 mR	

____	29.	Film/screen cassettes, CR cassettes, and the image intensifier are all examples of a/an
a.	processor	c.	grid	
b.	image receptor	d.	bucky	

____	30.	One advantage of digital fluoroscopy over conventional fluoroscopy is:
a.	no radiation dose	d.	all of the above	
b.	the post processing image enhancement	e.	A and B	
c.	the increased patient dose	

RA 202 Physics Class 2
Answer Section

MULTIPLE CHOICE

	1.	ANS:	A

	2.	ANS:	C

	3.	ANS:	B

	4.	ANS:	D

	5.	ANS:	C

	6.	ANS:	B

	7.	ANS:	B

	8.	ANS:	C

	9.	ANS:	C

	10.	ANS:	D

	11.	ANS:	B

	12.	ANS:	D

	13.	ANS:	C

	14.	ANS:	C

	15.	ANS:	A

	16.	ANS:	C

	17.	ANS:	D

	18.	ANS:	C

	19.	ANS:	D

	20.	ANS:	C

	21.	ANS:	A

	22.	ANS:	B

	23.	ANS:	B

	24.	ANS:	D

	25.	ANS:	A

	26.	ANS:	A

	27.	ANS:	B

	28.	ANS:	C

	29.	ANS:	B

	30.	ANS:	B