Question

A hundred years later, applications of Einstein's discovery still have beneficial effects. Modern x-ray machines emit photons of shorter wavelength than those that were used just a couple of decades ago. This change is beneficial for medical and dental patients because it reduces the health risk from exposure to radiation. Which of the following is a scientifically valid reason that this change should be beneficial?

1) By using shorter wavelength photons, beams of the same intensity contain fewer photons, thus reducing the number of photons that can damage human cells.

2) Shorter wavelength photons carry less momentum and thus cause less damage when they interact with biological tissues. 3) The shorter wavelength photons have less energy than the longer wavelength photons that were once used.

4) Shorter wavelength photons diffract more and are thus more likely to pass around living cells.

5) Shorter wavelength photons are not wide enough to interact with objects as large as biological cells.

Answer 1

Correct answer is

5) Shorter wavelength photons are not wide enough to interact with objects as large as biological cells.

All the 4 options are incorrect because intensity and energy are inversely proportional to wavelength so if shorter wavelength is use intensity and energy and momentum are increased so first three options are incorrect and longer wavelength diffracts more than shorter wavelength so 4th option is also incorrect.

Shorter wavelength penetartes less than longer wavelength hence 5th option is correct.