Q6 of 59 Page 395

If the operating potential in an X-ray tube is increased by 1%, by what percentage does the cut-off wavelength decrease?

Given:


Let


λ be the cut off wavelength and V be the operating potential in the X-ray tube.
Then,



Here,
h = Planck’s constant
c = Speed of light


If the operating voltage is increased by 1%, then the new operating voltage will be given by


V’=V+1/100×V= 1.01



V Cut-off wavelength on increasing the operating voltage is given by



difference in wavelength =


Percentage change in the wavelength is given by


=11.01=0.9901 = 1% (approx.)


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