Physics for IGCSE & O level - Waves And Sounds (Section 4 - No. 5)
In the case of ultrasound use in metal testing, what feature makes a flaw detectable?
Reflection of ultrasound
Absorption of ultrasound
Refraction of ultrasound
Diffraction of ultrasound
Explication
A flaw will be detectable, because a signal will be reflected, instead of just travelling through a homogeneous material.