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Following results are observed when ...

Following results are observed when sodium metal is irradiated with different wavelength Calculate ( a) threshold wavelength and ( b) plank s constant

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Take wavelength `(lambda_(n))` in nm abd `v_(n) ` in `mn^(_1)` of 1,2,3 observation
Threshold wavelength `=(lambda_(0) nm = 10 ^(9) lambda _(0) M`
`= (hc )/( lambda_(0) xx 10^(9))` = work function
Emitted energy (E ) = `(hc )/( 10^(9) xx lambda _(n))`
`lambda_(0)` = 530 .89 nm =531 threshold wavelength
Calculation of h planks constant
Put value of `lambda ` and `lambda_(0)` in observation :
`(hxx 3 xx 10^(8) (531 - 500))/(10^(9)(531) (500)) = (1)/(2) (9.1 xx 10^(31) kg ) (2.55 xx 10^(5))^(2)`
`=84464 xx 10^(-36)`
`8.4464 xx 10^(34)` plank constant
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