Misconceptions

#	Misconception	Why It's Wrong	Correct Statement
1	"Increasing intensity of light always causes emission"	Intensity only increases photon count; each photon has fixed energy hν; if hν < φ, no photon can eject an electron	Emission requires ν ≥ ν_{0}; intensity determines photocurrent but not whether emission occurs
2	"Stopping potential $V_{0}$ increases with intensity"	$V_{0}$ = (hν − φ)/e has no intensity term	$V_{0}$ depends only on frequency; intensity affects only saturation current
3	"Photons travel at different speeds depending on their energy"	Common confusion with particles — heavier particles are slower	All photons travel at c = $3 \times 10^{8}$ m/s in vacuum regardless of energy or frequency
4	"A photon can be 'broken into smaller pieces' to provide cumulative energy"	Photon interaction is all-or-nothing; one photon → one electron (in standard photoelectric effect)	Energy transfer is quantised; you can't store photon energy and wait for enough to accumulate
5	"de Broglie waves are physical waves that carry energy through space"	Matter waves are probability amplitude waves, not mechanical oscillations	The de Broglie wavelength predicts diffraction/interference patterns; it does not mean the electron is physically oscillating
6	"Electrons have no wave nature because they have mass"	This was the pre-1924 view. Davisson-Germer disproved it	Every particle with momentum p has wavelength λ = h/p; confirmed experimentally
7	"λ = 1.227/√V nm works for all charged particles"	Derived using m = m_e and q = e specifically	Valid ONLY for electrons; protons, alpha particles require λ = h/√(2mqV) with their specific m and q
8	"Threshold frequency is the same for all metals"	Different metals have different work functions φ; ν_{0} = φ/h varies	Each metal has a unique work function and therefore a unique threshold frequency
9	"The photoelectric effect and Compton effect are the same"	Both involve photon-electron interaction, but mechanisms differ	Photoelectric effect: photon absorbed, electron ejected (complete transfer). Compton: photon scatters (partial transfer), electron recoils with deflected photon
10	"Higher frequency light is always more intense than lower frequency light"	Frequency and intensity are independent: intensity = (photons/s) × hν	A dim UV source can have lower intensity than a bright red source; frequency and intensity are independent quantities