(a)(1) State the energy transformations which take place during the operation of a modern x-ray tube.
(ii) Distinguish between hard and soft x-rays.
(iii) State three uses of x-rays.
(iv) Mention one hazard of over-exposure to x-rays in a radiological laboratory, and indicate any two safety precautions.
(b) A possible fusion reaction is \(^2_1 H + ^2_1 H \to ^3_1H + ^1_1H + Q\)
where Q is the energy released as a result of the reaction. If Q = 4.03 MeV, calculate the atomic mass of \(^3_1H\) in atomic mass units. (\(^2_1 H = 2.01410 U; ^1_1H = 1.00783 U; 1U = 931 MeV\))
Verified Correct Answer: .
Physical Principles & Numerical Solution
(i) Electrical \(to\) thermal \(to\) mechanical (kinetic energy) \(to\) thermal \(to\) electromagnetic
(ii) Distinction between hard and soft X-rays
Hard X-rays
Soft x-rays
(i) High (target) voltage
(ii) short wavelength
(iii) High penetration
(iv) produced by high voltage
Low (target) voltage
Long wavelength
Low penetration
Produced by low voltage
(iii) Uses:
- Used to detect hidden cracks in materials
- Used to detect alteration to work of art
- To show broken bones in human body
- used in crystallography i.e. to study crystals
- used in diagnosis of ulcer
(iv) Hazards: genetic mutations
- skin burn
- leukemia
- Tissue damage
- Tissue damage
- baldness
- graying
- cataracts
(v) Safety precautions:
use of dosimeter, badges of GM counters
- wearing of lead coats
- Periodic medical counters
- wearing of lead coats
- periodic medical check up
(b)
\(^2_1H + ^2_1H \to ^3_1H + ^1_1H + Q\)
Let atomic mass unit of tritium \(^3_1H\) be X
2.01410 x 2 x 931 = (x + 1.00783) 931 + 4.03
\(\frac{3750.254 - 4.03}{931}\) = x + 1.00783
4.0238 - 1.0078 = x
3.106 = x
Source: Myschool Past Questions Archive (Record #54152)