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AS 2 Waves, Photons and Medical Physics

6 dot points across 6 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How is physics used to image the body and treat patients?

The production and use of X-rays, ultrasound imaging and the acoustic impedance principle, and the use of radioactive tracers in medicine.
A CCEA A-Level Physics answer on the production and medical use of X-rays, ultrasound imaging and the role of acoustic impedance and the coupling gel, and the use of radioactive tracers and half-life in diagnosis.
12 min answer →

Why does the photoelectric effect show that light comes in photons?

The photon model and the energy of a photon, the photoelectric effect, the work function and threshold frequency, and Einstein's photoelectric equation.
A CCEA A-Level Physics answer on the photon model and the energy of a photon, the photoelectric effect and why it needs photons, the work function and threshold frequency, and Einstein's photoelectric equation with stopping voltage.
12 min answer →

How does light bend at boundaries, and how do lenses form images?

Refraction and refractive index, total internal reflection and the critical angle, optical fibres, and image formation by converging and diverging lenses.
A CCEA A-Level Physics answer on refraction and the refractive index, Snell's law, total internal reflection and the critical angle, optical fibres, and image formation by converging and diverging lenses using the lens equation.
12 min answer →

What happens when waves overlap, and how do stationary waves form?

The principle of superposition, coherence and path difference, two-source and double-slit interference, diffraction, and stationary waves on strings and in pipes.
A CCEA A-Level Physics answer on the principle of superposition, coherence and path difference, double-slit and two-source interference, diffraction through gaps and gratings, and stationary waves on strings and in air columns.
12 min answer →

How can particles behave like waves, and what is the de Broglie wavelength?

Wave-particle duality, electron diffraction as evidence for the wave nature of particles, the de Broglie wavelength, and atomic energy levels and line spectra.
A CCEA A-Level Physics answer on wave-particle duality, electron diffraction as evidence for the wave nature of matter, the de Broglie wavelength, and how atomic energy levels produce line emission and absorption spectra.
11 min answer →

What are the properties shared by all waves, and how do we describe them?

Transverse and longitudinal waves, the wave quantities and the wave equation, the relationship between intensity and amplitude, and polarisation.
A CCEA A-Level Physics answer on transverse and longitudinal waves, the wave quantities of wavelength, frequency, period and speed, the wave equation, the link between intensity and amplitude, and polarisation.
12 min answer →