The threshold frequency for a certain metal is `v_(0)` when light of frequency v = `2v_(0)` is incident on it . The maximum velocity of photoelectrons
The threshold frequency for a certain metal is `v_(0)` when light of frequency v = `2v_(0)` is incident on it . The maximum velocity of photoelectrons is `4 xx 10^(6)` m/s . If the frequency of incident radiation is increase to 5`v_(0)` , the maximum velocity of photo electrons in m/s will be .
A. `(4)/(5) xx 10^(6)`
B. `2 xx 10^(6)`
C. `8 xx 10^(6)`
D. `2 xx 10^(7)`
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Correct Answer - C
`(1)/(2) mV^(2)= h (v - v_(0))`
Case I : v = `2v_(0)`
`(1)/(2) mV_(1)^(2) = hv_(0) " " ….(1)`
for `v = 5 v_(0)`
`(1)/(2) mV_(2)^(2) = 4 h v_(0) " " ……(2)`
`(2) div (1)`
`V_(2)^(2) = 4 V_(1)`
or `V_(2) = 2V_(1)`
= `2 xx 4 xx 10^(6) = 8 xx 10^(6)`
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