ABR 1 – Physics Questions And Answers With Complete Solutions
12 views 0 purchase
Course
Medical physics certification
Institution
Medical Physics Certification
US attenuation rule of thumb correct answer: 0.5 dB/cm*MHz in soft tissue
Lens dose is calculated at what depth? correct answer: 0.3 cm
How many HVLs in a collimator head? correct answer: 2% transmission, so 0.02=2^(-n)-> n=5.6, 6 HVL
Temperature and pressure correction correct answe...
ABR 1 – Physics Questions And Answers
With Complete Solutions
US attenuation rule of thumb correct answer: 0.5 dB/cm*MHz in soft tissue
Lens dose is calculated at what depth? correct answer: 0.3 cm
How many HVLs in a collimator head? correct answer: 2% transmission, so 0.02=2^(-n)-> n=5.6, 6 HVL
Temperature and pressure correction correct answer: P0T/T0P, T0=295.2K
To maintain an accuracy of 1/x, how many bits are necessary? correct answer: 2^y=x, y=lnx/ln2
ex: 1 ppm -> 2^y=10^6-> 6ln(10)/ln(2)=19.93->20 bits
Given an air Kema = D mGy, what is the corresponding exposure? correct answer: D mGy = D*10^-3 Gy->D*10^-3/(33.8 J/C)/(2.58*10^-4 C/Kg*R)
Identify intensity vs distance graphs for a point source, line source, and plane source correct answer: point source will be ~1/r^2, line source ~thetaf*thetai/h, plane source of radius r will be ~ ln(r^2+h^2/h^2) on CAX
physical and biological half-life correct answer: N(t)=N_0*exp{-{0.693/Tr+0.693/Tb}} For beta decay, what is the average energy of the beta particle? correct answer: 1/3 E Max
For a radioactive isotope with a half-life of T 1/2 and an initial activity of A, how many disintegrations occur between T 1/2 and 2T 1/2? correct answer: A=lambda*N
N0 = A0/lambda-> A0/2lambda-A0/4lambda=A0/4lambda
HVL and TVL equations correct answer: Transmitted intensity = 10^(-x/TVL)=2^(-x/HVL)
Ion chamber: 1 cGy per 0.25 nC. What is the size of the ion chamber? correct answer: (0.25 nC/cGy/1.3 kg/m^3)->(0.25/1.3
nC*m^3/J)*(W/e)-> 0.25*33.97*10^-9/1.3 m^3
Given a magnetic field of strength x T, find the energy needed to
take a proton from parallel to anti-parallel correct answer: B=x T
h_bar = 6.626*1-^-34/2pi J*s*radian
phi = 2.68*10^8 radiation/T*s for protons
E = B*phi*h_bar
A source with activity of x Bq has a half-life of y days. What is the initial amount of atoms? correct answer: A = x = N0*lambda
lambda = 0.693/y
N0=xy*(24 hrs/day)*(60 min/hr)*(60 s/min)/0.693
Equations for total kerma, air kerma, and collisional kerma correct answer: K=phi(mu_tr/rho)
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Classroom. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $10.99. You're not tied to anything after your purchase.
