Physics 7408/3BD June 2021

The AQA A-level Physics Paper 3B (November 2021), Option D (Turning Points in Physics), investigates key historical experiments and theoretical developments. Topics include electron diffraction and the de Broglie hypothesis, Maxwell′s electromagnetic wave theory, Hertz′s experiments, and the Michelson-Morley interferometer. Questions focus on the measurement of wave properties, verification of Maxwell’s equations, stationary waves, and the significance of null results in detecting the ether. Additionally, relativistic time dilation and particle decay in different reference frames are analyzed. Keywords: AQA Physics, turning points, electron diffraction, de Broglie, Maxwell’s theory, Michelson-Morley, time dilation, Hertz experiments.