PH-01 NEET 2026 Exam Strategy — High-Yield Facts and Question Patterns — Summary

High-Yield NEET Facts (answer these in under 10 seconds)

$V_{0}$ when intensity doubles → Unchanged. $V_{0}$ = (hν − φ)/e, no intensity term.
Slope of KE_max vs ν graph → h (Planck's constant). Same for ALL metals.
Slope of $V_{0}$ vs ν graph → h/e. Same for ALL metals.
de Broglie λ for electron at V = 100 V → 1.227/√100 = 0.1227 nm.
λ_e/λ_p at same V → √(m_p/m_e) ≈ √1836 ≈ 42.8 ≈ 43.
Davisson-Germer key numbers → 54 V, 50°, Ni crystal, 1927.
Photon energy at λ = 400 nm → 1240/400 = 3.1 eV.
Threshold wavelength for φ = 4.14 eV → 1240/4.14 ≈ 300 nm.

Most Tested Question Types (with frequency)

Question Type	NEET Frequency	Key Formula
$V_{0}$ vs intensity conceptual	Very High	$V_{0}$ unchanged
KE_max from λ and φ	Very High	E = 1240/λ(nm) eV; KE_max = E − φ
λ for electron through V	High	λ = 1.227/√V nm
Graph slope identification	High	KE slope = h; $V_{0}$ slope = h/e
Mass ratio wavelength comparison	Moderate	λ ∝ 1/√m at same V
Two-wavelength h determination	Moderate	Subtract two e $V_{0}$ = hν − φ equations
Threshold wavelength calculation	Moderate	λ_{0} = 1240/φ(eV) nm
Davisson-Germer conceptual	Low-Moderate	Wave nature of electrons confirmed

Exam-Day Decision Rules

If asked about $V_{0}$ and intensity: $V_{0}$ = UNCHANGED (100% of NEET questions).
If asked about photon energy: use 1240 eV·nm shortcut.
If asked about electron wavelength from V: use 1.227/√V nm shortcut.
If asked about mass ratio comparison: write λ ∝ 1/√m, then take the ratio.
If asked which graph slope is which: "K for Key = h; V needs e underneath = h/e."
NEVER apply 1.227/√V to protons or alpha particles.