Week 5

Question 1

Does blue light or orange light have a larger index of refraction in glass?

Answer 1

Blue

Question 2

What photon energies are selectively filtered in medical imaging techniques?

Answer 2

Lower

Question 3

Why does a gas discharge tube has a certain color?

Answer 3

The gas radiated only a few discrete wavelengths

Question 4

Why is it necessary to collimate the light source before using the prism to disperse the light?

Answer 4

So that the light rays entering the prism are parallel

Question 5

What is the similarity between MRI and radiation from a gas lamp?

Answer 5

They are both examples of line radiation

Question 6

Suppose that in Part 5.2.4 of the experiment you held one of these filters between the prism and the telescope. What would you see?

Answer 6

A red line

Question 7

Which of the following does NOT help the eye compensate for chromatic aberrations?

Answer 7

The fovea reflects the radiation in the yellow region of the spectrum.

Question 8

How can CT image sofft tissues with x-rays?
-It measures the x-ray penetration along each ray.
-Tissue densities are fed into a computer and viewed as a gray-shaded image.
-The beam is rotated around the body section to produce views from many angles.

Answer 8

All of the above contribute to create the CT image of soft tissues with x-rays.

Question 9

Why are lower energy photons filtered out in medical x-ray imaging?
-They only contribute to the patient exposure to the harmful radiation.
-They do not contribute to the image formation.
-They are quickly attenuated by tissue and therefore do not penetrate the body well.
-All of the above are reasons why these photons are filtered out.

Answer 9

All of the above are reasons why these photons are filtered out