1.(a)()explainwhyx-rayscanbeusedtoproducephotographsoffracturesin
bones.(ii)Listfourusesofxraysotherthaninmedicine
(b)Statetheenergytransformationswhichtakesplaceduringtheoperationofan
x-raytube.
(c)(i)explainthreenameddangerstowhichhumanbeingsmaybeexposedwhen
subjectedtolargedosesofxrays.(ii)Statetwoprecautionsthatmustbetaken
bypersonsworkingwithx-rays.
(d)Inanx-raytube,anelectronisacceleratedfromresttowardsatungstentarget
biasedatapotentialof33KV.Calcuate,fortheelectron,the(i)kineticenergy(ii)
velocity.
-34-31-8-19
{h=6.6x10Js;Me=9.1x10kg;c=3.0x10ms-1;e=1.6x10C}
(a)(i) X-rays can be used to produce photographs of fractures in bones because they can pass through soft tissues but are absorbed by denser materials like bones, creating a contrast that can be captured on film or a digital sensor.
(ii) Four uses of x-rays other than in medicine:
1. Industrial inspection and quality control
2. Security screening at airports
3. Material analysis in research laboratories
4. Non-destructive testing in engineering and manufacturing processes
(b) Energy transformations during the operation of an x-ray tube:
1. Electrical energy is converted into kinetic energy of the electrons as they are accelerated towards the target.
2. Kinetic energy of the electrons is converted into x-ray photons when they hit the target.
(c)(i) Three dangers to which human beings may be exposed when subjected to large doses of x-rays:
1. Increased risk of cancer due to DNA damage
2. Radiation burns
3. Radiation sickness
(ii) Two precautions that must be taken by persons working with x-rays:
1. Use proper shielding such as lead aprons and protective barriers
2. Minimize exposure time and distance from the radiation source
(d) Given:
Potential difference (V) = 33 kV = 33 x 10^3 V
Mass of electron (m) = 9.1 x 10^-31 kg
Charge of electron (e) = 1.6 x 10^-19 C
(i) Kinetic energy (K.E) = eV
K.E = (1.6 x 10^-19 C) * (33 x 10^3 V)
K.E = 52.8 x 10^-16 J
(ii) Velocity (v) = sqrt(2K.E / m)
v = sqrt((2 * 52.8 x 10^-16 J) / 9.1 x 10^-31 kg)
v = sqrt(115.2 x 10^15 / 9.1 x 10^-31)
v = sqrt(1.27 x 10^46)
v = 3.57 x 10^23 m/s (approx.)