Impedance
Find Z for ρ=1000 kg m⁻³ and c=1500 m s⁻¹.
Reflection
Why is coupling gel used in ultrasound?
Pulse–echo
An echo returns in 52 μs at 1540 m s⁻¹. Find depth.
Doppler
What happens to shift as beam angle approaches 90°?
X-ray tube
State two energy transfers in an X-ray tube.
Attenuation
μ=0.30 cm⁻¹ and x=4.0 cm. Find I/I₀.
CT
Why are many projection angles required?
PET
Why are two photons detected in coincidence?
Safety
State the ALARA principle.