DP Physics (last assessment 2024)
Question 18M.3.HL.TZ1.b
| Date | May 2018 | Marks available | [Maximum mark: 2] | Reference code | 18M.3.HL.TZ1.b |
| Level | HL | Paper | 3 | Time zone | TZ1 |
| Command term | Describe | Question number | b | Adapted from | N/A |
b.
[Maximum mark: 2]
18M.3.HL.TZ1.b
Describe one advantage and one disadvantage of using high frequencies ultrasound over low frequencies ultra sound for medical imaging.
[2]
Markscheme
ADVANTAGES
the wavelength must be less than the size of the object being imaged to avoid diffraction effects
the frequency must be high to ensure several full wavelengths in the pulse
DISADVANTAGES
the depth of the organ being imaged must be considered (no more than 200 wavelengths)
attenuation increases at higher frequencies
[1] for advantages, [1] for disadvantages.
[2 marks]