Two identical photocathodes receive light of frequencies \[{{f}_{1}}\] and\[{{f}_{2}}\]. If the velocities of the photo electrons (of mass m) coming out are respectively

\[{{v}_{1}}+{{v}_{2}}={{\left[ \frac{2h}{m}\left( {{f}_{1}}+{{f}_{2}} \right) \right]}^{1/2}}\]

\[v_{1}^{2}-v_{2}^{2}=\frac{2h}{m}\left( {{f}_{1}}-{{f}_{2}} \right)\]

\[v_{1}^{2}+v_{2}^{2}=\frac{2h}{m}\left( {{f}_{1}}+{{f}_{2}} \right)\]

\[{{v}_{1}}-{{v}_{2}}={{\left[ \frac{2h}{m}\left( {{f}_{1}}-{{f}_{2}} \right) \right]}^{1/2}}\]

Two identical photocathodes receive light of frequencies \[{{f}_{1}}\]

1.	Two identical photocathodes receive light of frequencies \[{{f}_{1}}\] and\[{{f}_{2}}\]. If the velocities of the photo electrons (of mass m) coming out are respectively
A.	\[v_{1}^{2}-v_{2}^{2}=\frac{2h}{m}\left( {{f}_{1}}-{{f}_{2}} \right)\]
B.	\[{{v}_{1}}+{{v}_{2}}={{\left[ \frac{2h}{m}\left( {{f}_{1}}+{{f}_{2}} \right) \right]}^{1/2}}\]
C.	\[v_{1}^{2}+v_{2}^{2}=\frac{2h}{m}\left( {{f}_{1}}+{{f}_{2}} \right)\]
D.	\[{{v}_{1}}-{{v}_{2}}={{\left[ \frac{2h}{m}\left( {{f}_{1}}-{{f}_{2}} \right) \right]}^{1/2}}\]
Answer» B. \[{{v}_{1}}+{{v}_{2}}={{\left[ \frac{2h}{m}\left( {{f}_{1}}+{{f}_{2}} \right) \right]}^{1/2}}\]