H2 Physics.

Mechanics is rising; quantum/nuclear is fading

Comparing 2018-And Earlier vs 2023+ papers:

+1.4pp  dynamics                   (4.0% → 5.4%)
+1.2pp  forces                     (6.0% → 7.2%)
+1.1pp  measurement                (3.6% → 4.7%)
+1.1pp  Circular Motion            (3.9% → 5.0%)
+1.0pp  Alternating Current        (1.1% → 2.1%)
+0.9pp  momentum                   (2.0% → 2.9%)
+0.9pp  Kinetic Theory             (1.0% → 1.9%)

-2.5pp  Quantum Physics            (7.3% → 4.7%)
-1.7pp  Nuclear Physics            (7.6% → 5.9%)
-1.5pp  Thermal Physics            (4.4% → 2.9%)
-1.2pp  Dc Circuits                (4.3% → 3.1%)
-1.1pp  Photoelectric Effect       (3.1% → 2.0%)
-0.9pp  semiconductors             (1.1% → 0.2%)

Quantum and nuclear are still the Most Tagged topics overall, but their share of recent papers has dropped meaningfully — likely a syllabus or emphasis shift toward classical/applied mechanics. Don't Over Prep on photoelectric or semiconductors based on TYS frequency — the recent papers feature them less.

measurement rising is a quiet signal worth taking seriously: more recent papers test experimental design and uncertainty analysis.

The "study these together" topic clusters

Top Co Occurring topic pairs (questions tagged with both):

340  oscillations + Simple Harmonic Motion       (basically the same topic)
247  Photoelectric Effect + Quantum Physics
242  interference + superposition
229  kinematics + Projectile Motion
226  equilibrium + forces
166  superposition + waves
151  electromagnetism + Magnetic Fields
142  dynamics + forces
138  equilibrium + moments
130  dynamics + momentum

Practical use: when you build a problem set, group these — solving one half usually requires the other. The oscillations/SHM pair being the strongest Co Occurrence (×4 the next highest) suggests the tagger is Double Tagging redundant labels; you can fold them in your prep.