Two radiations with photon energies 0.9 eV and 3.3 eV respectively are falling on a metallic surface successively. If the work function of the metal is 0.6 eV, then the ratio of maximum speeds of emitted electrons will be…………………

Options

A. `1 : 4`
B. `1 : 3`
C. `1 : 1`
D. `1 : 9`

Answer

B

Explanation

`v_(1_(max)) = sqrt((2(h upsilon - phi))/(m)) = sqrt((2(0.9 - 0.6))/(m)) = sqrt((2(0.3))/(m))`
`v_(2_(max)) = sqrt((2(h upsilon - phi))/(m)) = sqrt((2(3.3-0.6))/(m)) = sqrt((2(2.7))/(m))`
`(v_(1_(max)))/(v_(2_(max)))=sqrt((2(0.3))/(m))xx sqrt((m)/(2(2.7)))=sqrt((0.3)/(2.7))=(1)/(3)`
`(v_(1) : v_(2))_(max) = 1 : 3`