KEmax=λhc−ϕp=2mKmaxp=2 m(λhc−ϕ)dA−B=2R=2[qBp]
dAB=eB22 m(λhc−ϕ)=eB8 m(λhc−ϕ)
JEE Main 2025 — Physics Modern Physics
A monochromatic light is incident on a metallic plate having work function ϕ. An electron, emitted normally to the plate from a point A with maximum kinetic energy, enters a constant magnetic field, perpendicular to the initial velocity of electron. The electron passes through a curve and hits back the plate at a point B. The distance between A and B is :
(Given : The magnitude of charge of an electron is e and mass is m,h is Planck's constant and c is velocity of light. Take the magnetic field exists throughout the path of electron)
Held on 2 Apr 2025 · Verified 6 Jul 2026.
2 m(λhc−ϕ)/eB
m(λhc−ϕ)/eB
8 m(λhc−ϕ)/eB
2 m(λhc−ϕ)/eB
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