An X-ray tube operated at `40 k V` emits a continous X-ray spectrum with a short wavelength limit `lambda_(min) = 0.310 Å`. Calculate Plank's constant.

Explanation

We have ,
`lambda_(min) = (hc)/(e V) or h = (e V lambda_(min))/( c)`
Here, `e = 1.6 xx 10^(-19) coulomb, V = 40 k V = 40 xx 10^(3) V`
(i)`lambda_(min) = 0.310 Å = 0.310 xx 10^(-10) m`
`c = 3 xx 10^(8)m s^(-1)`
`:. h = ((1.6 xx 10^(-19)) xx(40 xx 10^(3)) xx 0.310 xx 10^(-10))/(3 xx 10^(8))`
(ii) ` = 6.61 xx 10^(-34) J-s`