A beam of light of wavelength `lambda` is incident on a metal having work function `phi` and placed on a metal having work function `phi` and placed in a magnetic field B. The most energetic electrons emitted perpendicular to the field are bent in circular arcs of radius R. Then

Options

A. `B =(mv)/(eR)`, where `(hc)/(lambda) =phi +(1)/(2)mv^(2)`
B. `B =(mR)/(eV)`, where `(hc)/(lambda) =phi +(1)/(2) mv^(2)`
C. `B =(mv)/(eR)`, where `(hc)/(lambda) +phi =(1)/(2) mv^(2)`
D. none

Answer

A

Explanation

NA