A-LevelPhysicsMedical physics9702/42 · Oct/Nov 2017 · Q46 Marks
Explain the principles behind the generation of ultrasound waves for diagnosis in medicine.
- (a)Explain the principles behind the generation of ultrasound waves for diagnosis in medicine.[5]
- (b)Ultrasound frequencies as high as 10 MHz are used in medical diagnosis. Suggest one advantage of the use of high-frequency ultrasound rather than lower-frequency ultrasound.[1]
Mark scheme
Marking points from the official mark scheme (Oct/Nov 2017). The mark or mark type is shown in brackets.
- [1] (a) quartz/piezo-electric and crystal/transducer
- [1] (a) p.d. across crystal causes it to distort
- [1] (a) applying alternating p.d. causes oscillations/vibrations
- [1] (a) when applied frequency is natural frequency, crystal resonates
- [1] (a) natural frequency of crystal is in ultrasound range
- [1] (b) small(er) structures can be resolved/observed/identified
Write your answer and get it marked
On Oracle Prep you can write or photograph your own answer and have it marked by AI against this mark scheme, with feedback on what you missed.
Sign up free →