DP Physics (last assessment 2024)
Question 19M.3.HL.TZ2.aii
Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.3.HL.TZ2.aii |
Level | HL | Paper | 3 | Time zone | TZ2 |
Command term | Suggest | Question number | aii | Adapted from | N/A |
aii.
[Maximum mark: 2]
19M.3.HL.TZ2.aii
An ultrasound A-scan is performed on a patient.
Suggest why ultrasound gel is necessary during an ultrasound examination.
[2]
Markscheme
gel has similar Z to skin
OR
gel prevents acoustic mismatch ✔
without gel much ultrasound is reflected at skin
OR
gel increases ultrasound transmission ✔
OWTTE
Examiners report
Most candidates mentioned that the gel improves the transmission of ultrasound. On quite a few occasions candidates seemed to confuse acoustic impedance and refractive index.
