Photons of wavelength λ are incident on a metal. The most energetic electrons ejected from the metal are bent into a circular arc of radius R by a perpendicular magnetic field having magnitude B. The work function of the metal is
A. \(\frac{\mathrm{hc}}{\lambda}-\mathrm{m}_{\mathrm{e}}+\frac{\mathrm{e}^{2} \mathrm{~B}^{2} \mathrm{R}^{2}}{2 \mathrm{~m}_{\mathrm{e}}}\)
B. \(\frac{\mathrm{hc}}{\lambda}+2 \mathrm{me}\left[\frac{\mathrm{eBR}}{2 \mathrm{~m}_{\mathrm{e}}}\right]^{2}\)
C. \(\frac{\mathrm{hc}}{\lambda}-\mathrm{m}_{\mathrm{e}} \mathrm{C}^{2} \frac{\mathrm{e}^{2} \mathrm{~B}^{2} \mathrm{R}^{2}}{2 \mathrm{~m}_{\mathrm{e}}}\)
D. \(\frac{\mathrm{hc}}{\lambda}-2 \mathrm{~m}_{\mathrm{e}}\left[\frac{\mathrm{eBR}}{2 \mathrm{~m}_{\mathrm{e}}}\right]^{2}\)
Answer:D
Photons of wavelength λ are incident on a metal. The most energetic electrons ejected from the metal are bent into a circular arc of radius R by a perpendicular magnetic field having magnitude B. The work function of the metal is
A. \(\frac{\mathrm{hc}}{\lambda}-\mathrm{m}_{\mathrm{e}}+\frac{\mathrm{e}^{2} \mathrm{~B}^{2} \mathrm{R}^{2}}{2 \mathrm{~m}_{\mathrm{e}}}\) B. \(\frac{\mathrm{hc}}{\lambda}+2 \mathrm{me}\left[\frac{\mathrm{eBR}}{2 \mathrm{~m}_{\mathrm{e}}}\right]^{2}\) C. \(\frac{\mathrm{hc}}{\lambda}-\mathrm{m}_{\mathrm{e}} \mathrm{C}^{2} \frac{\mathrm{e}^{2} \mathrm{~B}^{2} \mathrm{R}^{2}}{2 \mathrm{~m}_{\mathrm{e}}}\) D. \(\frac{\mathrm{hc}}{\lambda}-2 \mathrm{~m}_{\mathrm{e}}\left[\frac{\mathrm{eBR}}{2 \mathrm{~m}_{\mathrm{e}}}\right]^{2}\)